CREDIT CARD FINANCE CHARGE

I have been with ABSA for about 9 years and I just find them to be complete *******s!! I took out a ABSA credit card and was not advised that I will be debited a normal installment plus a finance charge! I haven't been using my credit card but yet have no flippen credit! my installments goes off without hassles then mid month i get deducted a finance charge on my credit card every month! this is ridiculous! how in the world do I build my credit with you people if you keep ripping me off! CONTACT ME ASAP. I will definitely be switching banks after this. PATHETIC SERVICE.