I booked a premium economy ticket and booked my seat 2 months in advance. I have a health problem and need to be in window it aisle. I booked my seat 23 A for my flight through for both sectors, Boston- Heathrow and Heathrow to Mumbai. When I tried to web cut in they wouldn’t allow me to until the 24 hour window. So as soon as the window began I web checked despite no urgency since I’d already blocked my seat. To my horror the website said the seat would be assigned at the airport. When I reached the airport they gave me a middle seat saying all other seats had shady been blocked. How? If I wasn’t allowed to book my seat while en checking how did anyone else? Why did I receive that message?!!! Does virgin Atlantic choose specific passengers to not allow seat choice (and that too after blocking yer seat 2 months ago when I booked yr ticket)? Why did the airline not allow me but allow other passengers to block their seats? Interestingly my onward flight has my seat blocked as 23A! I had my boarding pass. It’s going to be a traumatic flight and I have no choice! I might throw up, keep getting up unfortunately disturbing other passengers inadvertently. VA systems and attitude and technology are crap!!!!