Mtn cancellation

I am so disappointed at mtn at their service they have given me I can’t even write am so emotional at what they did I have been trying to cancel my contract as it has expired but no what they did was add on more now I owe R1700 in these hard time where will I get R1700 and pay for something I didn’t even us I feel it’s so not fair I have been trying to get myself out of debt for years for them to just put me back like that I have all call references that I have made trying to cancel even the stores don’t help us anymore they just say call customer care now they have switched of my home Wi-Fi I can’t work anymore meaning am losing money