Mtn failed me as a customer

On the 25th, I made an online purchase for MTN home Wi-Fi (month to month contract). It was delivered to me on Tuesday the 29th... I plugged everything on and waited for the following day.... Surprisingly on Wednesday (the 30th) it only worked during the day, around 6pm there was no internet... I called in and was told to switch it off for few minutes to reset it but still there were no changes.... Yesterday when I called in the coverage department, I was told that there is no coverage in my area(Makapanstad, North West). The sales agent registered my wifi under incorrect address. Today I'm now receiving a reminder message for a debit order that is scheduled for 04/08/25 (September payment). My pay day is on the 26th of each month and I have recently waisted my money on something that is not working. I just called in to cancel and I'm told that cancelations are not done online I should go to the nearest MTN store, like how is that possible because I was told that this deal is only available online not at the store, hence I made an online purchase.