My name dragged into debt

<p>I'm a very unhappy customer that had a contract with Nashua mobile, I wasn't informed about Nashua mobile closing down and about my contract being handed oVer to mtn, I only found out when mtn started debiting money from my account monthly and previously with Nashua I had a monthly limit where my phone was soft locked and I would purchase my own airtime, I tried contacting mtn customer care after these deductions were done, I sent them several emails ,I was then given options that I could set my own limit on my mobile I did that but still they carried on debiting more than I expected, I tried again to contact them but I was never assisted...a few days back I was contacted by a debt collection company telling me they representing mtn demanding I make payment or else I'll be taken to court, I don't even know if these people are legit as they are really harassing me </p>