Home Loan interest increased

<p>I have 3 home loans with STD. I called Standard Bank homeloan to review my interest rate, for it to be decreased, 2 weeks back, which the agent did advice that it might be decreased or not. There was decrease in the prime interest rate/home loans base interest rate of 0.25%. I Received a letter from STD Home Loan which state "Following the decrease in the prime interest rate/home loans base interest rate of 0.25%, the base interest rate charged on the above account has been decreased to 10.25%, with effect from 2017-07-21." All my 3 home loans interest have increased to 13.20%. all my home loans installment has increased too. i have called the home loans department so many time to investigate, i still have not gotten reply, i called today, the agent told me that she was going to send me the update, i havent received any update, my homeloans are in area, because i need feedback to why is all my home loans interest rate increased and i received a letter that they have been decreased. all i get is calls from STD demanding payment when they not even giving me feedback regarding the all of sudden interest rates to 13.20%. help urgently </p>