I'd phone Virgin on 789. Ask them to block all Premium Rate SMS messages to your number. And ask them to refund charges you incurred if you didn't sign up for the texts in the first place.
You should also be able to respond to each of the Premium Rate services in turn with the message STOP ALL. But I'm not sure that doing so is 100% reliable. Hence it's best and easiest to phone Virgin and ask them to block them all at their end.