Jan Evans and Angela Evans, both aged 52, were angered by the service they received on the H1 bus that travels from the town to the University Hospital of North Tees, in Stockton.

Angela, who has rheumatoid arthritis and osteoporosis, was on her way back from the Stockton hospital when drivers rejected her disability pass and told her that instead of her journey being free as usual, she would have to pay £2.70 to get home.

Just days later Angela, who catches the bus in the town's York Road, encountered problems again when she was charged £4.50 for a full-price return ticket for her eight-year-old granddaughter, Chelsea Fletcher, instead of half fare wich she would normally pay.

Jan, who lives in the King Oswy Drive area of Hartlepool, said the first incident happened last Friday afternoon after she had visited her mum in hospital.

Jan said: "She uses it there and back all the time and it has never been a problem.

"This time, the driver refused to let her on unless she paid.

"She had to pay £2.70, but I was thinking if she did not have any money in her purse she would be stuck."

Angela said: "I was really quite upset about it. I have used the pass before, and it has been fine.

"When I got on he said 'we don't take them anymore'. I thought he was joking, but he made me pay."

Then on Wednesday Angela encountered problems again when she tried to use the service with her granddaughter and was over-charged for the youngster's fare, but was allowed on this occasion to use her pass.

Gary Walton, managing director of the service provider, Compass Royston Group Travel, said the disabled pass should have been accepted on the bus and Mrs Evans should have only been charged half-fare for a child.

He said they have been encountering "teething problems" after recently taking over the service, that is partly subsidised by Hartlepool Borough Council and partly by the Government's fuel duty rebate scheme.

He said: "This week has seen the introduction of a new super low-floor bus that meets all passenger requirements.

"However, not all has run smoothly with ticketing issues but the company can confirm these issues have been fully addressed.

"Drivers now carry copies of free concessionary passes for both Stockton and Hartlepool councils to help with easy recognition."

He said the company will be happy to reimburse the Evans for the tickets if they got in touch.