Glocell incompetencies

I had a contract with autopage which went into insolvency and was taken over by Glocell. My account was debited on the 15th of every month. I then cancelled the contract in 2016. To my surprise sometime last year I receive demand emails from their collectors that I owe them R1006. When I followed up with glocell they said my balance was R130.00.They had never communicated with me about this balance as I understood that the contract has been cancelled