I apologise if this has already been covered but I have a problem with my new phones I need fixed urgently. I have replaced my old work phones with a BT 3510 Twin set, which are plugged directly into a BT Openreach MK2 wall socket. The handset has no dial tone, and I am unable to make or receive calls with it, however... The new handset works perfectly on my neighbour's landline, so I know the phone itself is working. I have also plugged my old phone back in, which also works, and BT engineers tested the line several times with no faults showing. My question really is, why isn't my phone working on this line? And also, if I have to return them and buy different handsets, which ones will work of these do not?