You can make your reservation from your IATA registered travel agent with below given GDS codes.    

You may use VIP International Central Reservation Service in USA and CANADA :  1-800-604-4274 and 1-800-604-1116,
UK : 44-0365-22 66 00.

ONLINE RESERVATION

You can make your payments via credit card. Your reservation request will be verified with an e-mail.