MTN doing contract upgrades without customer approval/agreement

I have a problem with MTN i hand a contract with them now my contract is about to end in February. I've received an email stating that my application for upgrade is approved and my device will be sent. i didn't make any upgrades, I didn't get any call or agreed to any upgrade. Now i went to the their Branch they say i should call MTN to cancel because this was done online by them. I did contact then 3 weeks back they keep on sending me back and forth and say i will get a call in 24hours but nothing has happend. Im really dissapointed to MTN because currently i have financial difficult and i don't want any contract.