What to do to make xbox live work with my wireless virgin media combo?

My step son has xbox live and it worked up to 2 months ago, but since We moved house, virgin chaged the box and We tried to reprogram the whole thing and We called virgin media, that said they wanted an extra 60 quid to Tell us how to program the xbox live. We can't afford it and I don't think its right. We put in all the pass words but it just don't work. Can anybody help?