FNB's practice to increase interest rates

Credit card: My straight facility interest rate increased by 5% from 17.65% to 22.65%, from one month to the next (March to April), with no pre-alert, no default on my part. I queried the change and the rate was corrected and the additional financial charges were reversed. I never received any explanation as to how and why. <br> Cheque card Overdraft facility: Up until June I received a \rebate"on the financial charges and interest on my OD"