MS Caravan Dealer problems

HI After a bit of pratical advice. I bought 2008 caravan from a local dealer(he was a Man in a field with 20 caravans)  he promised me the caravan had had a full check and was covered with a 3rd party warranty. So first trip out, water pump didnt't work probably wiring, contacted the warranty company who said wiring isn't covered. So I paid £118 to get it fixed from a NCC approved repairer. Pump now works but the tap leaks water everywhere. So it obvioously wasn't fully checked at all. So the dealler refers me to the warranty company, the warranty company say taps aren't covered only mechanics. So my question is do I chase the dealer with phone calls and threaten court action and all that nonsense or do I pay £40 for a new tap £40 labour and not bother? Life is short and I'm too busy to really chase the dealer in to court etc.So it depends how far I have to take it until he fixes it. Also if he takes weeks to fix it, I can't use the van ( well I can use it without water)