I was on a flight from Toronto to Budapest in December, connecting through Heathrow. Bad weather caused us to leave Toronto late but we made up some time in the air and arrived at the gate just before 7am. My connecting flight was scheduled for 8am with the gate closing at 7:40. I'd already checked in online and had only carry-on luggage. However, upon our descent into Heathrow an announcement was made to passengers on connecting flights. BA had taken it upon themselves to change a bunch of people's flights to later ones. Maybe this wasn't a big deal to people flying to Manchester and departing just 1 hour later than anticipated. However, my 8am ticket for Budapest got changed to 1:30pm, more than 5 hours later than anticipated. When I told a flight attendant I wanted to try to make the 8am flight, she gave me the whole, "The airport is very large and you need to get to a different terminal - you can't do it on time" mumbo jumbo. When I told her that should be for me to decide, she told me to push through the other passengers when we land, run to my next gate and "good luck- maybe you'll still get on". I did that and actually arrived at the gate at 7:35, even before some other passengers. (God forbid BA would put passengers onto a cart and ensure they got to the gate as opposed to making them wait for buses and run their ass off through the terminal) However, when I presented my original boarding pass, they said I had been taken off the flight and my boarding pass was no longer valid. They called a gentleman on the plane and told him I was there with my original pass and no luggage to check. He said no. I was then told to go complain to Connections. When I spoke with the manager, he said the flight attendant deceived me into thinking I could still get on the original flight because she probably just wanted me 'out of her face'. I was handed a voucher for food & drink and sent on my way. What was supposed to be 2 days in Budapest turned out to be 1.5 days. I have since sent complaints to BA customer service online, sent tweets to them and Alex Cruz (CEO), and sent actual signed letters from myself to Alex Cruz and the two top Customer Experience people, only to find out that those letters just get passed to the same customer service people who I've been dealing with all along. In short, I've been told that they will do nothing for me. BA changed my flight without my consent, their staff flat out lied to me and deceived me, and they refuse to provide any sort of compensation, nor do they seem to have taken my complaint seriously. I will NEVER fly BA again in my life.