Cell of the network with the person who is responsable

MTN cancelled my contract service by mistake Day 4 after 2 shop visits ,808 calls , new sim and hundred of calls to mtn my cell is still not active mesg.- not resisted on network emergency calls only No one at MTN can solve their mistake . How do you just lose a customer's after 17 years Extremely poor service and no one seems to know what they are doing .What they tell me for 4 days now " just and hour reboot your phone and it will be fixed " well that hour are 4 days now .