Scheduled multiple segments with domestic and international flights. Three of the segments were changed and we were never notified. Layovers changed increasing more than 3 hours for one segment and 3 hours for another. The only reason we found out about the change is because we looked online 3 days before leaving. Spent over an hour on the phone. All I got was "sorry"over and over. The rep could not tell us why we were not nipotified. We will not deal with them again.