Mnt

I got a mifi modem/router 3months ago, it's been paid every month, have not been able to use it once! It's keeps on saying no internet connection, went in to the shop and they did a Rica and said it'll be good to use the next day. Didn't happen, phoned customer care, holding on for 10min + every time, got a ref nr, it's been a week later and still nothing, I've been paying R700 rand for nothing every month. I've thought of canceling the debit order due to mtn failing to deliver a service they are being paid for. Please assist me.