payments to be paid to a closed account

We have closed an account at foschinis about 4 months ago, the cashier even cut the card in pieces , telling me that everything is closed and nothing is outstanding , from there it is going downhill and every month I receive sms and notifications of outstanding amounts , I dont know what amounts this is and why there is amounts outstanding , for what , I closed the account , this is most unacceptable to keep consumers at ransom for payment if I know for a fact that the account and everything connected to it was closed