Help ! I sold 3 SBD for 0.00007 btc but should it be 0.002 btc! whats happening

I am new here and tried to sell 3 SBD , I should have recieved 0.002 btc but instead I am being paid 0.00007 btc which is 10x lower.

Also I read the value of SBD or SD is equavalent to US dollar.

the buy and sell are showing different values  https://blocktrades.us/

Selling  5 SBD gives you 0.00132682 bitcoins 

but buying 5 SBD  needs 0.00334889 bitcoins

Please can someone explain hats happening