Why the service was disconnected from my phone although I tried to rectify the problem by contacting MTN customer care by phone and e-mail. and by

I got a cellphone contract with MTN and a telemarketer call me and offered me what I thought was an upgrade October 2021. DSV delivered two MTN routers but I got a contract with Jenny.co.za. I immediately contacted Mondo Customer Care and a Miranda Khumalo arranged contract cancellation on 28 October 2021. Routers were collected on 04/11/21. Service to my phone was cancelled on 10/01/22 due to none payment of debit order amount R1293.00 in January 2022. My usual debit order are R355.00. I contacted MTN customer care and received a Ref No *** and the person said it will be rectified and a double debit of R355 will be deducted on Feb 2022 but the phone was disconnected from service. I lodge a query with Mondo Customer Care and they said on 11/01/2022 an urgent follow up was sent to MTN. Since then to now no service on my phone.