United Airlines - Harassment by United Airlines

My parents traveled from Newark , USA to Mumbai, India on *th Aug, ****. They had requested for wheel chairs as they are both hold and my mother suffers from cancer-last stage and father suffers from lung ailment. We had pre-booked it but despite that they were refused. After boarding plane, there was a medical emergency with a passenger and therefore the flight detoured to Iceland and dropped off the passenger. Since United Airlines had a protocol to not fly beyond ** hours, they returned to Newark, USA. In the mean time, none of their customer care staff or their online platforms could provide the exact status causing immense panicky and confusion. Once again they boarded the plane the second time without wheel chair and a rude on ground staff. they were not served proper food and they were refused any support. We booked business class but there was no such service or hospitality extended. No chef curated menu, no cleanliness in toilets and many more such unfortunate happenings. we need compensation.