How to fix internet connection after lightening strike?

Can anyone help? My parents house was recently struke by lightening, with no structural damage luckily, however, 3 TVs, Sky, 3 lights, telephone and internet were all damaged. TV, sky and phone have been replaced and work ok, however, we are finding it impossible to get the internet connected. We've had replacement equipment and wires from the ISP and reloaded the software, but it is not connecting. I've event tried my laptop, which at first says it's connected, but then goes off. The telephone is connected to the same socket as the internet cable (using a filter (which was also changed) and the phone works ok. We have no idea what is the problem, and our ISP is not much help! Please help!!