Ulan Bator-Beijing train booking submission

Listing of various trains says: "Ulan Bator 13:20 1 / / 08:05
Ticket Fare: CNY1790/deluxe-sleeper, CNY1619/soft-sleeper, CNY1128/hard-sleeper"
However your website says there is no such place when booking. We are trying to book a 2 bed compartment for 7 July, Beijing to UB. Also would like to book UB to Sludyanka on 12 July