Sorry, I’ve never worked in PAL so I don’t know if I’ll be much help, but I was going to suggest that you try playing with your pixel aspect ratio setting. I have shot on “squeeze” in the past, though it was with a Sony Z1, which was the right choice, as your other choice was probably “crop” and you would have lost image that way.
If changing your pixel aspect ratios around doesn’t work, I have a more unorthodox method for you. What I’ve done in the past in a pinch is just create a sequence that has settings for what aspect ratio you want in your end product. Next you drop in your footage to the timeline, and when it asks you if you want to change the sequence settings to match your footage, say “no”. Once your footage is in there, it should look a little squeezed, so just grab your sizing handles and give the footage a little stretch to the edges of your frame. It should be pretty close if not exactly what you want it to look like.
Good luck,
Joe