Unhappy loyal client for more than 10 years

It is absolutely shocking how dishonest a service provider can be. We have been with tracker for more than 10 years. As soon as I wanted to cancel the contract they offered me a better system with better benefits for HALF the amount that we have been paying. On 12 March my husband spoke to tracker and gave me authorisation to deal with the situation on his behalf. A note was not made on the system. I have requested the contract to be cancelled with immediate effect. It was indeed cancelled on 12 March 2019. On 15 March 2019 another debit order went through and I have reversed the payment because the person who dealt with the cancellation told me that another debit order will not go through. We immediately on 12 March 2019 installed another tracker unit from another company and the "fob" was removed from the key. No one from tracker called to check if everything was ok, which means that the Tracker connect unit was not working, who knows for how long. We have ever since received SMS's and emails for an unpaid amount. Today 9 April I called Tracker and spoke to Luceal Smith who was absolutely rude and unhelpful. Eventually I have requested her to request the recording from the day of cancellation. She has put me on hold without telling me and eventually I just drop the call because I cannot be on hold forever. My husband again called and spoke to Lesley at finance who dealt with the situation and said Tracker will write off the amount based on the circumstances. Five stars for Lesley on how professionally he dealt with the matter. An absolute disgrace on how Luceal dealt with the matter.