Minecoin purchase unsuccessful

I try to purchase coins for Minecraft PE and it won't work. It did before several times however now it just says...
"It looks like we didn't finish things last time. Let's complete your purchase now. "
So I touch okay then it says....
"Sorry, we were unable to complete your purchase. Maybe check your internet connection."
My internet connection is fine. 

 

I have logged out of Itunes/App Store. Reinstalled Minecraft. Logged into the app store. Forced closed Minecraft. 

I have also tried to buy coins on other devices on different internet connections. Same problem. 

Nothing seems to fix this issue. 

 

Help Please!!!