What is the point of regulatory bodies?

I have had problems with a front door fitted by Everest 3 yrs ago. To be fair they came and replaced the doorl ast year, although over the last 5-6 months the problem is worse than ever . That suggests to me that the underlying problem is elswhere in the construction of the door frame. I contacted FENSA who told me they dont get involved and suggested i contact GGF who also told me they dont get involved in inspections or disputes! So what is the point of these federations if they wish to do nothing?