Funny enough, I got my deal yesterday too, similar to yours but mine is £30 a month + £20 activation fee. 100mb + player tv + talk more weekends - £50 bill credit - £50 refer a friend = £280 or £23.33 per month... XD
I am tempted to try and get them to match the new customer offer for this at £29/month. Presume you tried and they said that was the best they could do?
I just got 100mb broadband, telephone, and the basic tv with new modem and v6 box for £32 for 18months existing customer.
Virgin page states 'new customers only' - see bignasty187 comment, as an existing customer they were offered this for £39 p/m.