I will not say whether the site is a scam one way or the other. I have been their client time and again but have yet to make the trip to Kharkov. (life happens)
On the few occasions that I have had the need to contact the agency directly, the response has always been what I consider prompt considering the difference of time zones, professional, and courteous.
I do however find it interesting (read: suspicious) that after periods of time of me being 'inactive', the ladies seem to flock out of the woodwork once I have purchased some credits. Actually, there have been times where I didn't even have to buy credits, but merely use credits that had been dormant for months for me to come home to several emails in my inbox. The rest of the time, just crickets.
So guys, if you pursue this with both high hopes AND high expectations, likely you will be disappointed, and that is YOUR dysfunction.
Consider if you will, high hopes and LOW expectations and count your rewards a blessing.
Just my $0.02