Pathetic poor unacceptable service

I had contacted customer service in july just before debit order took off...to debit the full outstanding settlement balance ...that took place successful on the 21 july...to my surprise the account is still not closed today...they claim i have a balance outstanding...ive been calling and writing emails every month...when i finaly had a rest last month i receieved a letter confirmed zero balance and account closure...but to my surprise am still getting sms reminding me to pay...as the account is accumulated interest and open account fees...am tired of this...and i dont owe game a cent...instead they owe me my suffering...my airtime...data ...not forgetting my precious time.