Billing error / 9I***

I took out two Vodacom contracts for tablets in April 2015. These contracts were due to expire in April 2017. In April 2017, I called Vodacom and cancelled both contracts and it was confirmed that the last deduction would be in April. Then, in May another instalment was deducted but only for one device. I went to my bank to reverse the debit order and called Vodacom again to inform them that the contracts had expired and that I did the necessary cancellation with Felicia. In May the gentleman said he had cancelled the contract and that no further deductions would be made. No further deductions were made and I assumed that it was the end of story. Just to get an sms two weeks ago to say that I was handed over to their collections department. I called, and the consultant, said that one contract expired in April 2017 and the other in June 2017. My question is how is it that 2 contracts taken out on the same day, activated on the same day, same device and same contract amount, can have 2 different expiry dates. Then she said I should have check the contents of the contract. My question was then do you have contracts running for longer than 24 months and the answer was no. Then she changed the story and said there were months that I omitted payment. How could one contract be paid and the other not when I had one debit order for both contracts. When I asked her to identify the months of the supposed non-payments she couldn't give it to me. I asked her for her name and she just drop the call. I called back later that day and Constance could apparently not see who I spoke to earlier. This is very strange to me as all calls are recorded. I asked to speak to a supervisor / manager and Louise came to the phone. She could not understand why one contract was longer than the other but agreed that Vodacom has no terms longer than 24 months. She asked me to write a letter to ********** which I did but have not even received an acknowledgement of my letter. Yesterday, I received an account where they are requesting payment? Well, Vodacom, if you bothered to open my complaints letter you would've seen that I don't owe you any month... unless you can proof to me that two contracts taken out of the same day had two expiry dates. Lastly, when I cancelled in April, why didn't Felicia inform me that if I wish to cancel the "June" contract in April that I would be liable for a penalty. Even when I called in May, the gentleman, whose name I can't remember, also didn't mention anything about a penalty of the "June" contract

Sadie