MTN Cresta Mall pathetic and inefficient

I returned my MTN wifi router on 23 September 2024 at Killarney Mall, Gauteng and was given the number and options to choose when I cancel my account online. Whe. I went online, I was transferred to 3 people only to be told that I have to cancel my account at the store where I bought the router. I went to MTN Cresta Mall, Gauteng, on 28 September 2024 where I purchased the router in October 2023 to cancel the account. It seemed so easy.I gave the MTN salesperson the reference I received from MTN Killarney Mall for returning the router and in less than 10 minutes I was told the account was cancelled. I received a message saying my account would be cancelled on 28 September 2024, and then later another message saying my account would be cancelled on 30 September. I then received a bill which I paid in full on 01 October 2024. I thought everything was sorted until I received 2 messages this past week. One saying my account was overdue and another saying my service was suspended due to non payment. I emailed MTN customer services on 05 November, attaching all documents including a screenshot of the cancelation message. I got a response asking for my ID number, which I sent, and then heard nothing. I sent a follow up email on 08 November for feedback on my query. I then received a response referencing my cellphone account. I resend my documents, with a nessage saying that I wanted a response to my query, and wanted to speak to a supervisor that day. No response. Today 09 November, I went to MTN in Centurion Mall to query why I'm still receiving a bill for the cancelled account. Sazi Mkhutshwa and Thando Radebe were so efficient and helpful at the branch. They scrolled through the activity related to my router and service cancelation , and eventually found that there were 2 documents I needed to complete to cancel my home router account, which I was never given or informed to complete. Thando printed rhe forms and uoaded them for me, somwthing the Cresta Mall MTN staff should've done, but didn't. This has been the most frustrating and time consuming process I've ever had with MTN. I want my bill to be reversed since this situation resulted from inefficient MTN staff. This is the height of inefficiency and pathetic customer service.