Game Store card is a trap!!

I settled my Game store account and was even sent paid up letter on the 9th October 2019. Last week Friday (18 October) I then received a statement claiming that I owe them R152. Upon further investigation - I get told that the account underwent a credit review and will only actually be closed after the October billing cycle? This means the paid up letter accounted for nothing? I paid the amount owing in full but still get further charges??