Shapiro associates

I had a MTN account which expired on 8 Aug 2020, then I cancelled it on 8 July 2020. Then MTN said I must only cancel it on 8 August 2020.Then MTN extended the contract without notifying with another 2 months ,first MTN harrassed me for a year saying I must pay the 600 Rand, I refused,then I was handed over to Saya debt collection agency,seems like thy understood my explanation and left me alone.then about 2 years ago Shapiro associates started contacting me over and over, after countless emails they still harass me weekly ,in my e-mails I give the proof of MTN extended the contract without notifying me,so I cancelled my debit order and MTN tried to for another 2 months trying to deduct the amount,don't pay them,on their own website there's hundreds of people complaining about the same problem I have