Can university turn down appeal when they’ve failed to provide agreed exam adjustments

Daughter gets 25% extra time in her uni exams - she always uses this time. She sits exams in a room on her own as has severe anxiety. Recently sat an exam and we only realised a couple of days later when next exam was much longer that invigilator had not included her extra time in the finish time. Daughter had come out of the exam incredibly upset as for the first time had completely run out of time. Exam department admitted and apologised for the error, advised to put in for special consideration. This was turned down as the panel said exam result (74%) was similar to other results (79% and 93% in other modules) so extra time would have made no difference. The module that was affected previous exam and coursework in the high 90's.
On seeing her marked paper she lost 3/70 marks in the first 90 minutes, then when aware of only 30 minutes left (should have been 60) panicked and spiralled only got 7/30 marks left.
She has been told by Student Union only option is to appeal and if successful an uncapped resit. She has extreme exam anxiety and would have to give up weeks of holidays to study again. Seems incredibly unfair for unis error. Any advice would be appreciated please.