MTN customer (no) service

I app**** for a wifi router in April 2022. When I received it, it worked only when I test it at my work address, not my home. Finally found out MTN capoed the fixed router to only work at my work address, although I wanted it for my home. I have been trying now for a full year to get MTN to take it back and cancel the contract which I haven't been able to use once. Now they handed my account over for recovery. What the heck??? Why would I order a wifi in my own name for use at my work? They made a big mistake and now they don't want to rectify it. I am so sick of emailing over and over again with no positive result. Their customer service clearly is of no use to the customer!!