If a code doesn't work, I can in fact return a game to Best Buy to get another copy of the game.
If deemed defective. Typically that just means that customer walked up and said "This doesn't work!" and going through the motions of giving you the proper replacement media. Actual key codes are further regulated however and new ones aren't issued unless specifically by the game maker folks themselves. Any sort of exchange/return where a code is involved is always limited to a disc swap, nothing more.
That's how it is supposed to be handled. If it works out another way for you during your adventures to various retail stores then awesome, but you're lucking out as your sales associates don't seem to be aware of how to handle an instance such as that without going "OMG customer, gotta make them happy no matter what!" Commendable, but not the proper course of action given the EULA terms of today and the ever looming threat of piracy that every software developer out there is attempting to combat.
I tried to get a new code from RTW a number of times. (I think it was around 20 emails to just them). Due to the fact that their support was a bit lacking, they continued to tell me to buy the game, which I had already done. At one point, I was told to contact the retailer, so I did. Steam told me to clear my cache. That is all they would tell me. They would not give me a new code, nor would they refund my money. RTW would not refund my money as they did not sell the game to me. Additionally, their support did not speak English, so relaying my key issue was no small feat. (I am not attempting to sound ethnocentric. RTW support for the U.S. was in India and the many times I "spoke" to someone via chat, I got copy/paste responses that had nothing to do with the issue, so I am guessing that there was a language barrier).
That sucks big time, but that's just part of life. Things just aren't fair sometimes. As far as Steam is concerned, there wasn't anything wrong since RTW were the ones saying that everything was checking on their end as far as the digital sale went. Not Steam's fault.
The merchandise in my analogy was not defective. It was, however, missing. I also have to disagree with you in that I do believe that it was Steam's responsibility to issue a new code. Their merchandise may be intangible, but as a retailer, they should have some responsibility to ensure that they delivered the correct merchandise. They had multiple keys. They gave me the incorrect ones. I was asking that they give me the correct keys, which they would not do. They only attempted to fix an issue that was entirely unrelated to my problem.
They didn't blackmail me. It was more along the lines of extortion since no crimes were committed by either party. It is their policy to cancel your account if there is a chargeback. However, I didn't realize that this, combined with their "no refund" policy, gave them the right to not deliver on orders, take your money regardless, and tell you to stick it. It is my policy, (as a consumer), to get my money back if I paid for something and didn't get it.
Steam provides a set of tools to studios for which to publish their games via the Steam Platform. Any and all content and access barriers that are put up and maintained are the responsibility of those that are using the tools for which to put the material on Steam. All Steam does is ask that a demonstration of some sort is provided to them before giving the green light for they allow you to start using their SDK tools to publish that game on Steam.
http://www.steampowered.com/steamworks/
Your plight stemmed from a really crappy customer experience with RTW, something that Steam has no control over since the publishing part of the entire setup, down to the sale of keys on Steam and other products provided by that company, are the responsibility of the company. Steam didn't directly sell you the key, it was RTW that used Steam to sell you the key.
None of this was a fault of Steam, but RTW putting it together in a poor manner where you are now in your current situation of being out $100 and sitting on a disabled Steam account.
The only thing you could fault Steam for is perhaps a lack of ongoing quality control since RTW was the culprit here, but it wouldn't be any different if another retailer, digital or not, were in Steam's place in that case. However, Steam does hold you accountable on it's marketplace which is something that a walk-in shop can't quite do. It's another hoop to jump through to try and get your money back if you felt slighted in some fashion, but one that shouldn't come up as long as you bring the complaint to the right people. In your case, it was the late Realtime Worlds. They were the ones that didn't deliver, not Steam.
Steam wouldn't have any problem helping you get this whole thing cleared up so as you can carry on with your Steam account. You'll probably just have to dig a little deeper and get some results.
Were Steam really so cumbersome to the point that resolution via support couldn't be obtained, it would've died out years ago in it's infancy.