Perfectly legitimate. People enter into addenda to written contract by verbal agreement all the time. Those addenda carry the same weight as a written contract, provided both parties agree in retrospect as to the terms of that verbal contract. It would be hard for US to deny having verbally agreed to those terms when they took the initiative to call to renege on the verbal contract. I suspect that if gso2pit wanted to push the issue, he could be awarded $35 or one free pass to the club (most likely US's choice) if he took them to small claims court.
Having said that, it's worth neither the time nor the effort to do so. Furthermore, it still is beside the main point, namely that even if US doesn't have a legal obligation to honor their verbal commitment, they have a business obligation to do so.
Let us not forget that one of WN's greatest strengths is their ability to make their customers feel like they got an honest deal. The legacy carriers tend to do quite the opposite, with a laundry list of fees for nearly everything. Even if the customer technically "agreed" to those terms by buying the ticket, non-frequent travelers don't really know or understand those terms, and feel like they're being cheated. This is what drives them to WN.
Having said that, it's worth neither the time nor the effort to do so. Furthermore, it still is beside the main point, namely that even if US doesn't have a legal obligation to honor their verbal commitment, they have a business obligation to do so.
Let us not forget that one of WN's greatest strengths is their ability to make their customers feel like they got an honest deal. The legacy carriers tend to do quite the opposite, with a laundry list of fees for nearly everything. Even if the customer technically "agreed" to those terms by buying the ticket, non-frequent travelers don't really know or understand those terms, and feel like they're being cheated. This is what drives them to WN.