Terrible Service from MTN for Home Router

I am having a horrible experience with Service Providers - MTN, and Telkom. I know the stores are franchised, but that does not excuse the brands' lack of accountability and service, particularly MTN. The LTE router kept losing signal because my house is situated in a ditch, so I returned the device on 01.09.2025 at the Eastgate branch, where it was purchased (Lower Level L). Some of the items were still wrapped in their original plastic and box when I returned the router. Joseph is the manager of the MTN store in Eastgate. After numerous trips to the store and phone calls, MTN is still allocating data to the device and trying to debit my account for the 'outstanding balance'. The consultant, Mfundo from the store, tried. He communicated via WhatsApp, logged the query twice, participated in a conference call with Nomthadazo from Retentions (both were helpful), but each said the other is liable for the refund. Nomfundo also spoke to retentions while I was in the store and included me in the email he sent on 6/7 January 2026. The reference number from 10 Dec 2025 is IRMS***_1. The router was returned on 1 Sept 2025. I want to be refunded for the inconvenience and my bank charges, and the interest I would have gained. Other debit orders were rejected because of the 'instalment' that MTN still wrongly assume I owe them.