Current balance doesn't change even after numerous payments

RCS "***" sent me an email that i owe Game account total R 17, 564.64 and should be paying them R 1,962.00 by end of October. I did pay the full R1962 end of October. I only use the account once buying on credit for R204 only yet when i went to the game store to view how much in my current ballance, it says to this date i owe " R16, 744.00. how is this possible. I've sent email no response, phoned the 086 number no answer after 20 minutes holding. Im struggling now to pay for my end of November installment without this issue being resolved.