MTN terrible service

MTN is the worst service provider. I took a month-to-month contract home internet service. I cancelled in February 2025, and the router was collected on the 17th of March because the MTN shop in Rosehill (Port Alfred). The bill keeps going up and it will mess up my credit score. They keep asking of i got an IRMS number.They keep sending me from one agent to another. I am not getting any joy.