Pending Cancellation

I entered into a contract with telkom September 2023 and requested a cancellation on Oct 2023, because they didnt load amount of data agreed upon contract. They requested me to return their router + simcard, now they'r telling me that they didn't get the device thus its difficult for them to proceed with cancellation. I've been calling them since last year October until now, but nothing its been solved and they keep debiting my account. Telkom is a BIG ****😭