Hello all, bit of a slightly complex case here, but trying to work out where I stand.

I was due to fly from Mty, Mexico to Dallas and then Lhr, U.K. Today via 1st leg AA economy 2nd BA Premium economy. (Part of a return journey).

My flight from Mty has been delayed 5 hours, American Airlines have therefore taken me off my BA flight to Heathrow and downgraded me to an economy ticket on an AA flight later in the day. There's no premium economy on AA and they don't appreciate I had a better than economy ticket...

There's no BA staff at Mty, so called the Mexico City office but got cut off when the lady was going to hand me to her supervisor.

Naturally I should be entitled to some compensation for the difference in fare (at a minimum & I believe there's some EU rules around this)...

Question I have though is this premium economy leg from Dallas to London was going to give me my tier points for silver (collection period ends next month) which I won't get if I don't fly it...

What happens in this situation, any ideas how BA would treat this?