MTN lawyers harrassing me

Horror dealing with MTN customer complaints department!!!!!!!! I am writting this review after four months because Mike Ramaboka from MTN complaints management team phoned me on the 23 April 2018 & promised that their attorneys wont contact me because the account is cancelled. Mike Ramaboka was provided with the affidavit & ID document on the 15th February. Account number :A ********** On the 20 September 2018 ,I received a call from Norton Attorneys telling me that I'm owing MTN a lot of money & I must pay to avoid legal action aginst me. My contract was due for upgrade, on the 08th and 19th December 2017, i received an SMS notifying me that i am eligible for an upgrade. I ignored the SMS about the upgrade , as i did not want to upgrade. on the 29th December 2017, I received an SMS that my MTN contract has been approved & upgraded. I immediately called MTN Secunda branch and informed them, then advised me to go to the Police and report the matter as *****. On the 30th December 2017, i went to MTN Tzaneen branch, and the consultant informed me to do an Affidavit with SAPS. I then submitted it to the branch. On the 15th January 2018, I visited MTN Secunda branch since well i was not receiving any feedback from MTN, The consultant in Secunda branch said that he cannot lodge another call for the same matter because it will be a duplicate. He then advised me that all i can do is to reverse the funds when MTN bills my account. On the 22nd January 2018, i received statement of account from MTN and it stated that i owe them R799. on the 26th January 2018, MTN deducted R799 from my Standard bank account, i reversed the money back into my account as advised by the consultant at MTN Secunda. The 7th February 2018, i received an SMS stating that i now owe MTN R810.40, the sms also advised that this amount should be payed at ABSA. On the 13th February 2018, i received an SMS that my outgoing call facility has been suspended, that i should immediately the R810.10 at ABSA. Why is MTN attorneys calling me to pay after i was promised that the account is cancelled. I will not be threatened with legal actions knowing that i didnt upgrade any contract with MTN.