[graf_von_anonym]

The issue would appear to be oversubscription but all is not lost. As Virgin roll out 50mb services across the network they are increasing (or parallelling) capacity, which should do something to alleviate these sorts of issues. It's allegedly due to finish before the end of 'Summer', but from the depths of winter that may look quite far off.

While the Complaints procedure is probably the right route to go down, they'll probably only be able to offer you credit (continuing or otherwise) on the account. While it's possible that a network upgrade could get bumped up the priority list, the 50mb deployment is so significant that it's unlikely they'll be doing much more than contemplating work not already scheduled while it is ongoing. 50mb should do

Then, of course, they'll activate the Packet/Application/Routing-Analysis Network Operation Inhibiting Apparatus to arbitrarily disconnect you for watching Little Howard's Big Question on iPlayer or downloading a legitimately purchased musical file.