Gametap gametap.com Refusal to issue a refund. Terrible customer service. Internet

I saw an advertisement for the game Sniper Ghost Warrior. Gametap.com was offering a monthly membership to be able to play that game and some other games. So I signed up for the one month membership. After making the payment I downloaded Sniper Ghost Warrior and some other games. The only game that I was really interested in was Sniper Ghost Warrior but downloaded from Gametap it doesn't work. About half the games downloaded from Gametap don't work. So I requested a refund within 24 hours of signing up and paying for the one month membership. For some strange reason it takes a very long time to hear a response from them. One time it took me two days. The most recent email to them has been about 5 days and still no response from them. I have proof that the reason that Sniper Ghost Warrior downloaded from Gaemtap doesn't work because the download is corrupted. The proof is that when I downloaded the game from a different website and a different company then the game works. I deserve a refund from Gametap but they are ignoring me and refusing to make a refund.