poor poor service

I ordererd uncapped LTE with router from MWEB. Despite being told it was activated, it never worked. After a week I queried it and was told there was a compliance problem from their side, I cancelled the service which I thought was my right to do. They then said they would not take back the router, I had opened the box so it was second hand and I had to pay them R2000 plus the months service that was NEVER CONNECTED. I arranged to make a payment of R500 a month which they accepted and told me that they would query the services because they could see that the service was never activated. I made my first payment on 1 March and e mailed it and the e mail came back saying their mailbox was full. I was sure they would find it as I included my reference number. I have now been contacted by a debt collector saying they handed me over. I called them and they acknowledged receipt of payment and that it was allocated yet still handed me over. They don't seem to have a clue what they are doing and their customer service is terrible, They are making me pay for something i cancelled and refuse to take a brand new router back and even when I pay they hand me over. What a shocking company.