No one answers calls

Have been with this insurance for more than 3 years and the service level has declined drastically. I claimed for my windscreen on the 19 Oct. My claim was only attended to after numerous calls which Auth was provided on the 29 Oct. I am in the process of selling my car and need the telemetics to be uninstalled. I have been calling for the past 3 working days for more than 30 minutes and no one is answering their calls. I called the emergency line with the hope of being forwarded to the relevant team but with no luck. This is frustrating and unfortunately I will be cancelling my insurance with them.