DLA Assessment

I took my daughter for a DLA assessment today. They ran an hour late and then said that the assessor would be another 45 minutes as he had to write up his report for previous client. This would have taken appointment time from 3.00pm to 4.30pm. Also advised by that time the assessor would have said he didn't have enough time to assess her. She suffers from several debilitating illnesses and severe anxiety. All this has made her very ill. I was thinking of complaining to DLA or/and MP. Would this be worth it or will it have an adverse effect on her future assessment. (We had requested a morning appointment, but this was not taken into consideration.)