Collections for service not used by Mondo/MTN

In July 2025 I app**** for a router and and a cellphone contract with them, which after checking my finances , I decided to cancel with them. I received the items on the 25th of July and returned them within the 7days period, undamaged and the cancelation went through well. In August MTN debited from my account, I called both Mondo and MTN and Mondo consultant promised to escalate the matter and arrange for my refund which must happen in their 20 days cooling period. 20 days passed and on the 26th of August called Mondo again and was promised to be refunded in 21days on the 15th of September, another debit went through, called again and was told to wait for 14 days, today the 7th called Mondo again and the story changed, the lady said I owe MTN 9000 and she is unable to tell me why, I should call MTN and find out, as rude she was. Cut her off. Mondo is terrible, devious, evil, I would never recommend anyone to use it. They made me appear as a horrible payer to MTN. I am busy working this with MTN hoping for the best outcome, as for Mondo you are a terrible Company