I complained to Elderhostel and was told the only way that they would pay the $110 to change my ticket was for me to sign up for another trip with them. I was also told that they could cancel a trip at any time even after the full amount was paid. I never could get to speak to any supervisors.
Consumer Complaints & Reviews

I booked a trip through Elderhostel, paid a deposit and then paid the full amount when billed. Approximately a month after paying the full amount, the trip was cancelled. Unfortunately I had purchased a nonrefundable airline ticket which had to be changed or used by the time of the trip (approximately a month away).