I don't know. I guess I'm used to having the 24 hour cancel policy, especially in the case of a genuine mistake and website error. Seriously, noticing five minutes after booking and not being able to switch for free? That's not normal.
Also, guess I should have booked through Expedia. They offer 24-hour cancel, no questions asked. Instead, I decided it would be safer and better to book through Aeroflot.ru
Stupid!