They are quick to take your money but not as quick to pay you back your money when they are at fault

They are quick to take your money but not as quick to pay you back your money when they are at fault. They were debiting my account for months for devices that I did not have and were never activated (returned back to them the day after they were delivered and the contract cancelled). Now when I want my money, they have even resorted to ignoring my emails. I have emailed their customer care service, as well as their retentions department and yet... Crickets! Save yourself and don't bother with MTN!!