Poor customer service

I took a cell phone contract with Mtn early this year (February) and I also had the device insured in the same month.Now Because of Covid19, I decided that it was unnecessary for me to have the device insured since my movements were limited and I hardly went anywhere with it. I actually decided to cancel after I had paid for the insurance for 3 months. I sent an email to Mtn requesting that the insurance be canceled, even called several times but I was given the run around and got what sounded like excuses for them not to assist. I then received an sms stating that my insurance was canceled but the amount was still the same that was due on my statement, I thought maybe it was a technical glitch and that it was resolved. I still paid for the insurance in May and I still paid for it in June. After the June payment which is on the 15th I decided to contact them again. I received the same sms stating that the insurance is canceled on the 30th of June and that I should be aware of the 30 days notice and I was okay with that cause it meant I was going to pay for July. Then July passed, and in August they still billed me for a service that was no longer rendered, I checked my statement online and it reflected the same amount I was paying while the device was still insured but then the was no longer insured in August so I didn't understand why they had to bill me for that. I am still sending numerous emails with no assistance at all, the consultants are always, claiming that they have no idea what I am talking about, asking me for the same information every time I contact, they ignore my emails when I request that my premiums be refunded. At this point I am really thinking of disputing the debit order at once and reporting this matter to small claims court because I know that if I don't, they will still charge me in September. Nothing wastes time like complaining in this world, I can't be dealing with this matter every month.