Assume you are talking about speed over wifi. This is dependant on distance from the router and the device.
It is the speed to the router you need to measure. Use an ethernet cable from the router to your PC to get a more accurate reading. If this has increased then you need to look elsewhere re your phone.
Try posting in the Broadband Section of the Virgin forum. Plenty of experts on there.
This is not O2 and we are all customers here similar to yourself and cannot answer account type queries.
