DSK:

In May I traveled with my parents to Cabo San Lucas. We connected in IAH. My mother needs a wheelchair to get around, and it was noted in her PNR before we traveled.

We were assured by reservations and when we checked in that there would be a cart waiting for us in IAH.

When we got to IAH, yep, there was no electric cart or wheelchair (and we weren't the only ones requiring cart assistance from our flight). We stood around for 30 minutes waiting, and we almost missed our connection, like you.

Anyway, if you do contact the DOT, and need a few names to add to yours (need some fuel for your fire), feel free to contact me via email.