We bought the land that used to be a bluestone quarry. Within a year of living in the house built on the land, we started seeing cracks. The builder investigated and decided that the land is slipping away and even underpins won't work. The developer is contacted and we wanted a mediation to get compensation to get out of the mess. The developer is avoiding the mediation with many excuses while the builder is only willing to mediate when the developer is involved. Please advise what can I do?