Sadly here in the US I've had similar problems at DFW and MIA, with DFW being the absolute worst going back to pre-COVID days. In fact just a couple of weeks ago it took 1.5 hours to get retrieved from the assistance point at check in at DFW for a domestic flight - thankfully I had arrived 2 hours early knowing how bad it is. While I was waiting, multiple people came and then left limping away because they were afraid they were going to miss their flight. In the US at least, if you have issues with disability assistance, ask for the CRO - they are required to have one on duty at all times under the ACAA.