Cellphone contract complaint

I have a complaint about a contract and service from Mobi Warehouse, i app**** for a cellphone contract with them in December 2016, i recveived the phone and sim card on the 13/12/2016 and the contract started on the 01/01/2017 and it comes to an end in December 2018. as part of the contract i am supposed to receive R115 monthly airtime however for the month of November 2018 i didnt receive any airtime and when i contacted Mobi warehouse and spoke to a guy called JP i was told my contract came to an end in October and my number is now a pre-paid number but they collected a premium now today 20/11/2018 and he confirmed that they are also going to debit me in December.

i asked him how come they debiting me till december but i only got airtime till October, his explanation was that they received the sim card in their stock in Novemeber and it had R115 airtime and he also said they recharged the sim again in December of which i have no recallection of, so i asked him for proof of this in the form of a billing record or a recharge history. he told me they dont have access to that information anymore. i cannot belive that as a professional company they dont keep such records and if they dont have the records where is he seeing the information he was giving me about the airtime recharge.

my expected resolution is my airtime for the last 2 months or they much refund my R423 deducted today and cancel further deductions.