We moved the position of the rising main by connecting a length of 25mm mdpe to the existing 22mm or 3/4 inch (not sure which) black plastic pipe using one of the plastic couplings. The plumber used a plastic insert in teh 25mm but didnt put an insert in the old black pipe. Now its all buried in concrete and I have found a copper insert which I am sure he should have fitted in the old pipe. Before I confront him, what is the advice from you more knowledgable proffessionals please.