A cry for help

MTN is debiting my money, but i never has a phone on my disposal. I cancelled the contract before i could take the phone. Now MTN staff is busy saying the contract is cancelled, but MTN stil makeing debiting orders. Now my phone is blocked by MTN. I work with my phone, so the impact of their no service is putting me under so much stress. Somebody please help me, i have been following this for 3 month