This is a scam! Never buy from these crooks!
I made a booking on OMIO and due to a mistake I asked to cancel within 5 minutes. My booking had not been confirmed yet! I could not find any way to cancel online. I asked the support and they sent me a link where I was to do it but the link took me somewhere irrelevant. I sent several emails and every time I got reply with my "case number", but then never heard back. Several hours later I got email confirming my booking. At that point, on my booking page, I saw a place where I could cancel but it turned out that cancelling would cost me almost $100 or around 20% of the ticket price. This is theft!
And, on top of that, they say refund will take 15-20 days! Com'on!!!