This happened to a friend of mine, just bend the end of the pipe in an outwards position like a lip and they will grab nicely to the couplers.

 

They're typically used for exhaust applications.

 

The intercooler piping definately needs to be rolled at the end and also try putting hairspray on the pipe before you put the couplers on. I had to do it on my wrx because even with rolled piping they kept popping off over 20psi.