never received the item, yet they deduct the money

I ordered a laptop from MTN a few years ago, and had them deliver it to my place of work, which is Sea Harvest in Saldanha. This went without any problems.Within 7 days I had my laptop. This year, they phoned me to upgrade, and I decided to take a galaxy tab 4 10.1, at a cost of +-R250-R300 pm. I never received the item, yet they deduct the money from my bank account.I tried to phone them, but it's too costly to be put through to a certain person, only to hear you will again be put through to the next person, etc. I emailed them as well, absolutely no response from MTN whatsoever. It turns out MTN are not interested in the customer, only to take their money, whether it be legal, or *******. To me this is unacceptable, I need this contract to end with immediate effect, or have my Tab delivered. MTN, what a disgrace of a company :-(