Credit Card increase instead of decrease

I have a problem with the standard banks credit card...I am so traumatized by this bank...I have been paying my instalments each and every month without skipping..I don't even use the card...but the balance doesn't decrease instead it is increasing...my balance is still the same since from last year...when I call them they don't answer the phone you will hold till you drop...I don't even get clear answers from them...as far as I know..if I don't use the card and if I pay it every month the balance should go down...but his credit card goes up instead..I have checked on the balance on the 9th may 2019,and I have checked today's balance 11th May 2019 it's almost R1000 more compare to the previous balance...will I finish paying this nonsense or what?I feel so used and exploited right now...I even regret why did I have to take the credit card from Standard Bank