Hi all,

This is my first post so please don't ridicule me if I'm posting this in the wrong area.

I booked a roundtrip Aeromexico BCN>MEX with a layover in MAD. At time of booking the outbound MAD>MEX AM2 flight was on a 788 and the return leg MEX>MAD was the new 787-900.

I'm someone who's quite obsessive about seat selection and as my first time flying Aeromexico I wanted the best seat my award ticket will allow.

I noticed my seat assignments were suddenly changed. I had paid €100 for an Aermexico Plus window seat. They have reassigned me to a regular aisle seat at the back of a half empty plane for both legs. After calling they refuse to refund me or to put me back in my original seat and they say "You paid to RESERVE the seat which is not guaranteed. If you don't have a receipt to prove you paid for it we can't do anything". Now first of all this is ridiculous as their system doesn't automatically send a confirmation email with proof of purchase and even still, shouldn't they just even offer to place me back in a Plus seat?

I know that they changed the aircraft. They swapped the 788 to the 789 on the outbound and vice versa.

What can I do?