Game store are ********** and *****s

I've settled my account with game store on 31/01/2018 and i requested game store to close the account. Last week i received statement that shows i purchased something that cost R20 000 how possible because I've closed the account. I immediately contacted game store to inquire about this and shame they don't care. This is affecting my credit score and no one cares. I'm so disappointed with the kind of service I'm receiving from game store together with t rcs. Stay away from their account if you dont want to complicate your life. Now my bond application has been declined because of them