Service not provided

I was told while I was on the phone that my American Express card interest rate was changed to 0 percent for 1 year then it would be 3.5 after that.  There has been 2 payments of $199.20 from my bank account but my interest has continued at 16.99.  I talked with American Express they said nobody had lowered my interest rate. This is not what I was told. I will cancel further payments and expect the payments back that I have already paid. I will wait 24 hours to hear from Sebastian Parker to explain why what he said has not been done.