I booked through Lastminute.com a return flight which was later cancelled by the airline due to a schedule change.
I contacted their customer service and they promised to refund the whole amount. But later they kept for them a 20 euro processing fee (for some unknown reason...). It is over the 15% of the amount I payed for the flight...!
I tried to contact them various times to ask for further details but I have only received a couple of emails with no meaningful replies and then they stopped to reply.
Hidden processing fees + misleading and poor customer service = STAY AWAY FROM THEM!