Just a thought...could trading standards help? As it is a lack of service who h you paid for. If you speak to them, it gets logged and they can point you in the right direction for help. Make a record of dates, series of events before you speak to them. Even if not completely accurate, you will have a list of action taken ..(.or not) and promises made!
I've used Trading Standards a couple of times Ruth. Sometimes just the threat is enough to prompt some action but if not they really don't like it when TS first get in touch!
I've also used the Fraud Squad before now.