MTN And MONDO ****s

I got a call from Mondo promising me the world if I took out a specific contract . I did take it out and received the device in Jan . Once received I realized I was completely ****med. I called same day to return it. In march I received a bill from MTN for R16000. I cannot afford to pay that on a cellphone bill. I went to MTN who told me mondo had charged a cancellation fee. MTN wont take responsibility and I had to get hold of mondo. Mondo said they would pass a credit. To date they have still not passed a credit and all my phone lines have been suspended. I have been a client of MTN for close to 30 years and never missed a payment and I get treated like this because of the ****s they choose to work with. I am so disappointed. Never ever use MONDO and try and stay away from MTN