Not happy with Altech Autopage its a *******!

I am really unhappy with the way my account has been handled with Auto page.I did not renew my contract with this service provider,I had to give a 30day notice before cancelling my account with,which I called them and informed them.After 30 days the contract was cancelled and they transfered my to prepaid with the same number this was in 2013.Today I got a call from Nudebt they handed my account to their lawyers because im owning them,this is not right before i left i made sure all monies are paid as i was using a debit order.Please can someone call me and explain what is going on here.Please I need to know what is that Im owing urgently.<br> <br> This is really pathetic.When calling your call centre for an explanation there is no ine answering,what is going on guys with service ???