Key tag

I was offered a key tag jn July which I gladly accepted for R20 per month. Now the problem started when I couldn't link it to my vehicle and I called to notify them. They promised to call and help with linking as there was no option to add on my app, but they didn't call. After a few days of trying and waiting I called to cancel and I was assured that it has been canceled. They debited last month and I called to enquire I was told that they will refund me but they didn't. Now on their invoice again there's key tag amount. What does one have to do in order for them to cancel this key tag that is not even linked to my car.