MTN bad service

Worst service from Mtn and mondo, I've been going back and forth between the two companies and no one seems to know who should assist me. I've sent more than 10 emails and call them everyday and I'm still stuck with this home router I can't even connect to. I've been paying for the home router since April. They can't assist me with changing my address which their consultant failed to update . They are failing to change the address . They don't want to refund me the money they have been debiting me since April 3. They have refused to cancel the contract because they want to charge me a fee which I refuse to pay, they must take it from the money they have been debiting me

Both companies are not willing to resolve this issue.