My question involves collection proceedings in the State of: New York

Firstly all of my payments with my Capital One card have been on time since I have gotten the card. When I signed up for the card, it was for a 5.99% APR on purchases for the life of the card. Now, they decided to raise the APR to over 15%, saying they sent me a letter stating they were doing this, which I never received. When I asked how that was possible when the reason I signed up for the card in the first place was because the APR was guaranteed to remain at 5.99%, she didn't give me a good answer, sidestepping the question with hemming and hawing about the economy and about how it had nothing to do with payment history or anything. Again, I pressed them on how this was legal and didn't this constitute false advertisement and fraud? She quickly stated that she can't discuss this anymore and was there anything else she could help me with? I slammed the phone in her ear and am planning to contact an attorney and the NY attorney general regarding their deceptive advertising practices and fraud. I would also like to push for class action status as I have seen quite a few people complaining about similar things happening with Capital One "fixed APR for life" on ripoff reports, etc. I am so mad right now, I really don't even care if they can do it or not. I would rather make them spend tens of thousands of dollars to defend the lawsuit even if I have to pay my attorney to file it and work on it. It cannot, or at least should not, be legal to advertise fixed APR for life and then just raise it whenever they feel like it. Please let me know if I can have a reasonable chance of winning the suit, and if not if I have anything to gain by forcing them to defend the lawsuit, even if I can't win it. This is complete BS in my eyes and they need to pay for it one way or another. It would be like me agreeing to lend someone $100 with no interest, and then they come back to pay me the $100, tell them I decided they need to pay me $150.