I had a chat with directfx support but they do not have 15m expiries.
They have the following though:
60 seconds = 75%
5 minutes = 75%
10 minutes = 70%
30 minutes = 70%
60 minutes = 70%
They may add 15m expiries at a later date.
I dont know what they are talkiing about but if you look at trade I posted the second trade was taken on 15m expiry on gdmfx.Prob new mt4 tool dosnt have 15m since I didnt try it.