Tracker's sales reps lie about the terms and conditions

I've been a customer for over 4 years and was contacted by Tracker on 16 May with the offer of an upgraded system - the sales rep confirmed that as my contract was over 3 years old, I wouldn't need to cancel, I could just move over to the new system, get free installation of the new unit and removal of the old one at the same time. I accepted and the new unit was installed about 4 days later. An SMS the same day said I would be debited pro rata for the new contract for May. On the 26th of May, I was not only debited pro rata costs for May, but 2 premiums for June - one for the new contract (fine by me) but also for the old contract which apparently requires 30 days cancellation notice even though it is over 3 years old and therefore "out of contract". I call Tracker's Finance dept and they seem surprised that the sales rep didn't explain this. I have requested a recording of the call to prove this but it will take 7 days or more to obtain because of their backlog (clearly because a lot of irate customers have to request call recordings). I'm appalled that Tracker misleads clients this way. Had I know 30 days notice was still required, I'd have given notice on that day and told the rep to contact me again in 30 days with the offer of a new contract so I wouldn't have to pay 2 premiums in a month. Shoddy, underhanded sales tactics and a pathetic way to treat loyal customers. I expect a call back immediately to sort out a refund of one of the premiums or I will cancel and join Netstar.