The council removed my radiator, then when they went to replace it they had problems getting water into it, so after messing about with my tank and the pressure and stuff they found the problem was a screwed up piece of paper in the pipe left by the previous council man... since then I have only cold water coming out of my shower... I've rang them to complain but they say nothing they did could have caused this and have refused to come out... please help :(

What I think happened here is when they worked on your system they dislodged some mineral buildup in the pipe walls and now it's clogging your cold water ports on the cartridge.

Shut the water off and open up the valve. Remove the cartridge and check and clean the inlet ports. While the valve's open turn the water back on for a few seconds to flush out the supplies. Reassemble band test. Better now? Tom