MiWay does not return customer calls

I received an unsolicited call from MiWay. After agreeing to speak with the agent I am offered an excellent price on my vehicle insurance. I accept. I am told that I will receive a call to assist me in cancelling my existing cover. The call comes, I answer, the call drops. I don't hear from MiWay again. I call the call centre and leave a call-back request. I go online and send a message requesting a call back. I'm still waiting two weeks after the first call. I've cancelled my policy on the app before it has even taken effect. I have been promised a call from the retentions department. They say 72 hours (clearly they are not desperate to retain clients) it is 62 hours later and the office opens in 10 hours time.