Washington Mutual - Platinum Mastercard Review

i got this washington mutual platinum card about a year ago with a 19,000 dollar credit limit and a 11.99% interest rate. then they waited for me to spend 16,000 dollars on it and changed my interest rate to 21.99%. they are nothing but con artists trying to get your money. they're in it for nothing but the money and they're disguised as a bank. and how can they afford to give an 18-year-old a 19,000 dollar credit limit? they can't possibly have enough money to back that all up, which would actually be fraud.