Caravan problem

We found a small leak where the water comes in from pump, we contacted whale who sent us a new unit. As we are on a seasonal pitch we contacted a mobile engineer who was recommended. The engineer replaced the new unit and it was working fine. We went to do some shopping and when we came back no water coming from taps, we contacted the engineer who said it was working when he left and did not know what the problem could be,  but agreed to come back the next day, we waited never came and did not answer our calls.  We have now booked our caravan in with our dealer which with hindsight we should have done in the first place. The site does not have facilities but we stayed for 2 weeks anyway.  At least we saw the funny side of the situation we found ourselves in.