MTN - Estate Late going nowhere

Disgraceful service from MTN legal with regards to an Estate Late account. The early termination value was paid in September 2018 and I was assured that contract has been cancelled but ACCOUNT IS STILL ACTIVE and receiving sms's notifying me of outstanding balances. I cannot get through to MTN Legal Department via telephone and no one at customer care can assist me as account has been HANDED OVER even though early termination value has been paid.