15 posts later looks we have reached a consensus....
1) Get used to it
2) Leave and move to FTTP
Noted, you can't get FTTP in your area which sucks. So this is how i recommend you play it now.
1) Threaten to leave so that retentions department will lower your monthly price. When my contract was up i renewed on a retention deal (just what i do with everything tbh) but later my gaming was also becoming unusable, so i complained, i genuinely was gonna leave, but they lowered my bill even lower from the retention deal i was already on, so it was just too good a price to say no to, so i stayed.
2) Get a second BT DSL line put in just for gaming, believe me, even if you're far from the exchange, you'll still have a better multiplayer gaming experience on DSL than you will on Virgin. The money saved from option 1 can go towards your new DSL contract.