OUTSTANDING ACCOUNT????? NO

I received a call on Thursday 24 March 2016 from Hammond Pole attorneys, stating that I owe Vodacom an amount of R1680.00 almost a year after my contract is ended of which I was not informed about at all from Vodacom's side ( NO SMS, NO EMAIL NO MAIL NOTHING!!!!!!. A YEAR LATER?????.. , I even called the call centre to notify them to cancel my contract, as my phone is still in good working condition and I don't see the need to continue (Hammond pole advised that I cant cancel the contract over the phone I need to go directly to the branch)Vodacom never told me this when I contacted the call centre, also after cancelling my contract, I received a call from Vodacom again where they just wanted to follow up as to why im cancelling the contract, and they even offered that I stay on the contract as I use a lot of data of which I didn't .had an incident with my phone so I had to reapply for a new contract, I went to Vodacom to apply for a new contract gave them all my details and filled in documents and a few days later my application was declined due to me not having enough credit . surely VODACOM could then pick up on their system that there is an amount owed to them??SO UNPROFFESIONAL