MTN repeated faulty devices

I renewed my contract with MTN in December, I was fooled into thinking if you order a phone online it is actually MTN you are dealing with, to my surprise you deal with a different company altogether called Mondo. PLEASE NEVER EVER GET A PHONE ONLINE!! I received my device upon opening the package and switching on the phone it was evident the phone was faulty. After a huge issue to send the phone back to Mondo I managed to cancel the contract. They advised me the best way to upgrade is to go to an MTN franchise. I went and had to basically apply for a new contract as the *********** people at Mondo cancelled my contract and I was now on prepaid. Contract application done I received a Hisense H50 S, the phone worked for the most part but almost immediately I realized it loses signal constantly. I returned the phone within 7 days and received a new one, low and behold same issue. I cancelled the second contract on the 29th of December, it is now almost a month later and I am still struggling to get the contract cancelled as they need to decide if i need to pay a cancellation fee.... for a phone I do not have, and did not even have for 7 days in total!!! How is this possible, and how is it that the MTN Warehouse has this amount of faulty devices?