I just decided to post here as a warning for fellow travelers. Below is my sad story.
I bought a ticket from Airfasttickets.com (was routed there from Skyscanner) due to lower price.
Recently the second leg of my trip was changed (airline cancelled the flight and re-booked me for the flight departing 5 hours later). When I called the airline to check my option they told me that I can change my first flight to the later one free of charge as well, to shorten the layover time. Unfortunately, since I bought my ticket through Airfasttickets.com airline rep could not change it and advised me to call them. This is where the trouble started.
For 48 hours I tried to do this change to no avail. I called their "customer service" several times (waited on hold for ~30 minutes each time) and was told the following: "I forwarded your request to our ticketing department", "be patient" etc. I also send emails through their website (no reply). If you call them be prepared that the person you talk to can''t do anything to help you - they just "forward your request to the relevant department"! When I called last time I was told that there were no seats available on the flight I want, which was a blatant LIE! I called airline afterwards and confirmed, that the seats are in fact available!!!
Bottom line: if you see the name Airfasttickets.com - buy at your own risk. I had bad experiences with customer service in my life, but this company has a most incompetent and lazy staff you can imagine. They don't give a s***t about their customers.