Vodacom refuses to cancel my contract!

I took out a laptop & 3G contract in 2014, which ran its two-year course, the laptop debit deduction stopped after the 24months, but I have been struggling since 2016 to cancel the 3G contract. I don't have the SIM or Puk anymore, I tried phoning multiple numbers, visited stores across the Western Cape and the consultants keep on telling me nobody instore can assist. I then out of pure frustration put in a stop order at the bank, as this was now supposed to be on a "month to month" basis, now this contract is reflecting as a non payment on my credit score and still nobody at Vodacom can assist me, which mean I have paid over R8500 over 4 years and not even getting the benefit. The Treating Customers Fairly Act should prevent things like this from happening. I am to of ideas on how to cancel this contract!