Mtn Insurance canceled but they still debiting.

I had my mtn insurance canceled on the 26th of November 2019. They said my last debit will be in December 2019. Just to find out in January 2020 they are still billing me for useless insurance. Who couldn't even pay a small claim of R1000 but I've been a paying customer for years. It's really disappointing that such a big company can rob people of the money. I've Phoned them, visit them but nothing has been done. I regret ever opening a contract with them.