2017 CANCELLED CONTRACT COMES TO LIFE IN 2021!!!!!

I am so shocked and disgusted with Vodacom. I had a 2 year contract with them in 2015, which was cancelled on 2017. I did not upgrade but cancelled the contract 2017. Guess what? I received notice of overdue payment in 2021, YES 2021, for amount due of about R170.15....FOR WHAT AND AFTER HOW MANY YEARS THEY HAVE STARTED BILLING ME AGAIN IN 2021!!!! It took me three calls to ***, 082135 and ***, spoke to D.Giyiselani from collections, Tamara Naidoo at customer care, that couldn't help me, and then with Usha who opened a ***** case claiming that vodacom will contact me within 48hours (this was Friday 6 Aug, a week ago, but I have not received call back. I did however receive another call from collections yesterday 12 Aug to pay the outstanding balance and when I questioned the lady why she is calling me for a 2015 contract, she dropped the call in my ear. CAN SOMEONE THAT CAN DO THEIR JOB PROPERLY PLEASE CALL ME AND REMOVE THE COSTS FROM MY NAME UNLESS THEY CAN PROVE THAT I REINSTATED OR UPGRADED A NUMBER THAT IS SUSPENDID ***.