Mixtelematics poor communication- questionable charging

I had a vehicle covered by Mixtelematics for antitheft - tracking purposes. I sent and email on 13 March 2020 requesting a cancellation of the policy as I had sold the vehicle. I received a reply on 13 March 2020 indicating they had received email and a reference number was provided. Today 19 March I tried to phone to find out if the cancellation had been processed. What a mission - after 4 calls - and 4 dropped calls to cancelations Department - and answered by people with unclear names, I finally got through to cancellations. Here to be told that although I cancelled on 13 March , they are still going to charge me for April - as its one month notification. This is unfair - outlandish. Probably spurred on by my telephone calls - I then received a two emails on 19 March, one telling me that my cancellation request was on the 18 March!!??? - Go figure. Poor communication - poor PR - poor service - questionable charging. I would not recommend dealing with this company for antitheft / hijacking purposes