The mum of a brain-damaged toddler was forced to sit on the floor of a bus when passengers refused to move from the disabled area to accommodate her son's buggy.
Elderly passengers told Alisha Frost, 24, to fold up her buggy and sit two-year-old Jack on her knee.
The mum had boarded the Stagecoach bus X4 service in Cardiff to get home to Pontypridd after a rare shopping trip.
The full-time carer for her son, who has brain damage and cerebral palsy, said: "When we got on to the bus I noticed some people were sitting in the disabled area on the pull-down seats, so I asked the driver if he would be able to ask them to move so I could park my son's buggy there.
"He told me he wouldn't ask them for me and I needed to ask them myself."
She added: "I politely asked the people, who were in their 60s or 70s, if they would mind moving to one of the other free seats so I could park the buggy, but they said no.
"They told me they didn't have to move for me and told me to just fold the buggy up and sit my son on my knee.
"I explained that I couldn't do this as my son is disabled and he needs the correct support or he flings himself forwards. They still wouldn't move and the driver didn't get involved.
"In the end I had to sit on the floor and as I didn't have enough room to put the brake on the buggy I had to hold it myself so it wouldn't move as the bus drove."
The mum, who was left so distraught by the incident that she burst into tears, told Wales Online: "When I got home and told my mother, and my partner Steven, they were both so angry that people could have treated us so badly.
"I'm furious about the whole situation and have been so upset since - it's just wrong that we were treated in this way."
A spokesman for Stagecoach in South Wales said: "We are deeply concerned to learn of this incident.
"All of our drivers receive formal customer care training, so it is extremely disappointing to be told of this lady's and her child's experience, which falls far below the standard that we expect and regularly achieve from the vast majority of drivers employed by us.
"The matter is currently under investigation with a view to remedial action being taken and we offer our unreserved apologies to the lady in question and her son."
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