Not so ayoba mtn

So I have been a contract customer with mtn the bossa network for a good 14 years I reckon. But why did you mtn cancel my contract yourself without notifying me, only a sms saying I am on prepaid. I upgraded with a black friday deal with more minutes to call, as my work requires calling a lot. You send me the wrong phone, spoke to one of the service champs and they said they are sorry, they will collect the phone and send the correct phone. But no contract is canceled and trying to speak to the correct person at customer care who can help you is like finding your way through a maze blindfolded. Very very poor service.