David and Goliath

I took a contract out with Vodacom in February 2016 and due to various issues on a separate account, Vodacom took it upon themselves to disconnect this account even though there were no issues with it in October 2016. Since then I have made payments to Vodacom religiously each and every month in order to settle the outstanding amount according to the contract that I signed and I have made a total of 17 payments due on a 24 month contract, according to calculations. I have never once tried to run away from this responsibility at all despite the SIM card in question not been in a phone since October 2016. I suddenly get contacted by a debt collection agency saying that I apparently have been in breach of contract since October 2016 and that I still have another 15 months due on my account. Vodacom is not able to send me any statements reflecting this outstanding amount at all. The 10 payments made in 2017 totaling an amount of R3231.16 seems to have just disappeared and Vodacom collections department says that they are not able to send any sort of statement as their system doesn't allow breach of contract amounts to be reflected on statements. They are expecting money to be paid when they are not able to provide the proof accordingly. Once I had managed to get the statements that Vodacom has been sending me down to a R0 balance, Vodacom never once contacted me to confirm that there was still an outstanding amount (which I would have happily continued making payments on) but instead they just simply hand me over to the debt collection agency and according to them, any and all payments made in 2017 are null and void and apparently didn't happen despite those payments all reflecting as being successful according to my bank.