How can I extend the time watched for a purchased movie?

Due to work and school I cannot view movies purchase in one single seating. I purchased a movie and the next day it was no longer available. I must have missed the 24 hour viewing period of time. This has happened to me twice. Is there a way to request these two movies back in my inbox without paying again?
Give at least two-three days to watch a movie please!

What device?
What application?
Are you "purchasing" or "renting" the movies?