Shocking interest charge and interest rate

<p>I received my FNB Gold Credit card statement for Jan 2017 on last week Friday.</p> <p> </p> <p>I was shocked when I saw the month's interest charge of R584.99 - the highest the interest charge has ever been on my credit card since I got my credit card in 2014.</p> <p>Last month my balance on my credit card was about R15 857.10 before interest and fee charges. At the end of Dec 2016 interest of R130.53 was charged.</p> <p>This month my balance on my credit card was about R15 557.88 before interest and fee charges. At the end of Jan 2017 interest of R584.99 was charged.<br />How is this possible?</p> <p>Also upon my investigation into this matter, I realised that FNB has been charging me interest at a rate of 24.60% since March 2016.<br />I originally signed for a personalised interest rate of 22.70% in October 2015.</p> <p> </p> <p>I have emailed the credit card department at FNB twice this week and I have lodged a complaint on FNB's website, but up till now I have had no respnse whatsoever. </p> <p>Really dissapointed that after 3 years being with FNB and holding various FNB products (that I could have gone for at other banks), that I am treated this way.</p>