24/7 HomeRescue very bad experience

This is my second year service with them coming to an end in December, as per the contract they suppose to do boiler service and somehow they find a way to avoid this.

When I called very first time nearly two years back they said i need to pay my full yearly contract money to get my service and I paid. They said someone will call me in a month to do the service, he called me after few months and setup an appointment in few months. On the day of the month i took off from work and on the day he called me said this is cancelled now without any notification. by the time 6 months gone. Again went to customer service again the same happened and year gone this time and contract renewed to next year with the hope of get boiler server this time.

They say book service online but online always get a message
No Cluster Appointment Date Available to Book.

This is the same thing happens every time and in now end of second year, and try to call cancel my contract and they put me somewhere but get disconnects after 30 minutes.

Can I get my two years money back, really fed up with their service and would like to complain and get my money back. Please advise and share your experience in this.

Once my contract ends in Dec and not renewed, can I get the service they missed for two years?

When I called yesterday they said they put me in escalation, and the escalation is someone will call me in 28 days, What the hell is that, really really avoiding to do any boiler services.