Stuart Weddell says he's suffering from severe anxiety after working at HMP Birmingham.
The private contractor G4S has apologised to a 73-year-old woman left waiting six hours for hospital transport.
Sharon Mullen says she was forced to get a taxi home to Cliftonville, in Kent, at a cost of £112.59 following an NHS eye operation under general anaesthetic at St Thomas' Hospital in south London.
She had been told she would be taken home by G4S, which provides a non-emergency patient transport service, shortly after 15:00 GMT on 22 January.
She was still waiting at 21:00, and finally made the 80-mile journey home in a Uber car after a friend offered to pay the cost of the fare.
I was in terrible pain, and I just wanted to get home and go to bed.
You don't expect to be let down. Not at a time when you're vulnerable.
G4S patient transport services managing director, Russell Hobbs, said it had contacted Ms Mullen to apologise for "the poor service".
"We are investigating this complaint and will reimburse any costs incurred."
G4S, the world's largest security group, has had a good 2017, with revenue up 3.2% to £7.43bn - although that was short of the £7.55bn expected by analysts.
Pre-tax profits for the outsourcer were £75m higher at £386m.
Chief executive Ashley Almanza said the outlook for G4S was positive. "Our strong market positions, commercial discipline, growing technology-related revenues, positive cash generation and on-going productivity programmes provide substantial confidence that the group is well positioned to deliver a strong performance over the next three years.”