MTN refusing refund/credit for a home router that they didn't setup correctly for a month

I purchased a home router from MTN Bayside (Table View Mall). The device wasn't working for a month. My address pin location was wrong and they didn't set it up upon purchase as a home router and the correct communication channel wasn't setup. After a month they could do the setup after receiving training from MTN technicians. They still deducted the monthly fee and penalty fee for changing from a pocket router to a home router and refuse to reimburse me for the device not working for that month.