MTN invoicing months after cancellation.

Terrible Service. I have been trying to cancel my contract with MTN for the past year. I was in contact with the MTN retention office, after being notified that my contract will end December 2020, I get an invoice for 2021 Jan and February. These contract companies are completely unprofessional and continue debiting from your account with no remorse. I will never sign up for a cellphone contract with MTN again.