Mtn home router not working

Wow So disappointed with Mtn On the 9th of July I took a month to month uncapped home router and paid pro data for that month and also paid for August using my credit card,router was delivered on the 13th and it never worked.I then contacted Mtn support department for couple of days and they couldn't assist me cos they knew nothing about the new routers and was adviced to take it to the nearest Mtn which I did and it was confirmed that the router was not working and they booked it in while checking with them about the router I was adviced to go back to mtn shop to cancel the contract and make one in the branch as their routers are different.i went to cancel my contract and I called in to cancel the contract which I was told it's done.Amazingly on the 15 of July I had a debit order for the same amount I paid on the 9th (unauthorised debit order) and I called again to tell them that they debited my account in again.I then called my bank to reverse the money back into my account which was done and been calling almost everyday and getting a different story.been trying to get my refund back cos the router never worked at all instead I just got another debit order from Mtn with a huge amount.Been sending emails to more than 3 people but there's no response or feedback but when I was on the call they confirmed receiving emails from me. This is the worst service ever and inconvenience I've had with Mtn now my credit score is affected by all this