Chase Card Services From WAMU to hell! on % rate increase! Palatine Illinois

At the end of January 2009, I received a notice that Chase Bank now owned by Washington Mutual credit card account. In the letter, it stated "A Notice of Change in Terms". I immediately called and spoke to an individual by the name of Tanianla and was told that the promotion I had would remain the same. I opted to close out the account to ensure the 8% interest rate and wrote a letter as well. Then on my April statement my interest rate was a whopping 23.24%! I called and was put on hold for over an hour and spoke to several people and even had to call back because I asked to speak to a supervisior and no one ever came back to the phone. Everyone I spoke to, including the supervisor's had no record that I ever called on Feb 5, 2009. I pulled up my phone records which revealed that I had called on the date I stated and was on the phone for several minutes, which was proof that I had called. I was told that my account was still open and that I would be responsible for the increased interest because I had no proof of calling! I had a name and phone records, but they refused to relent. I have always paid all my bills on time, but at this point in time Chase Bank will just have to wait. I refuse to pay them another dime until something is done. Any suggestions to where I can go from here?

Chadwix78
San Antonio, Texas
U.S.A.