We had a new shower installed in the summer. 4 months later there are damp patches on the lounge ceiling (directly under the shower). Plumber came round to fix it. Now the problem is even worse!! We have contacted him several times, emailed pictures etc. He has replied today basically saying the "alleged leak" can't possibly be his fault!! AIBU to employ someone else to sort it? Or should we pursue this incompetent twat?