Help my Pebble car seat is stuck in ISOFIX Base

[Reeso76]

I have managed to get my pebble car seat stuck in the Easyfix ISOFIX base; I have only just realised it is not the correct base. THE lefthand side is completely stuck and I can't seem to release the isofix either. I am hoping I am not the first person to do this and there is a simple solution to get it all out of the car and the seat off the base. Please help!

We've got a different seat, but things that have helped - pulling the base forward to give you a bit more space.
Removing the headrest, again to get a little more space.

Good luck getting it out. DH fought with a seat for about half an hour one evening, and it was a compatible base!