Has anybody tried using this TRV
http://www.toolstation.com/index.html?code=48000
with Speedfit 10mm pipe ?

It has a brass reducer from 15mm but there is a large gap behind and however
I tighten it the pipe is skewed to one side as the olive compresses, then
pulls straight out at the end.

Toolstation claim it is okay for plastic pipe and suggest I phone the
manufacturer myself.

Has anybody had similar problems, or can explain how to get the pipe to stay
in properly.