Hannah Hopkins, 30, said she needed to get across the tracks at Worthing Railway Station last Monday but the lift was broken and staff refused to help.
Hannah, from Durrington, said she called to a conductor on the other side: “He said he could not help and I would have to go to Lancing.”
What is more, Hannah said he told her she would have to pay for the extra journey.
She added: “I was really upset, stuck on this platform with no way to get off apart from going to Lancing.”
Hannah said she shouted across to another member of staff, who went into the office, but then came out and went to sit in the waiting room instead of helping her.
She added: “I just wanted to get over to the other side. It’s not that difficult.
“There were people who could have helped but they ignored we were there.”
But two teenagers came to help – a boy and a girl about 17 years old – who helped carry the buggy down the stairs and back up the other side.
Hannah offered to buy them coffee but they declined payment for their good deed.
She said: “It makes a change because everybody criticises teenagers.”
She now wants to find them to thank them again, but did not get their names.
A spokesman for Southern, which runs the station, said: “We apologise sincerely to Ms Hopkins that the lifts being out of use made her journey even more difficult. Repairs were completed on Friday.
“A member of our staff did discuss helping by carrying her buggy, but unfortunately she had too much luggage for two people to take in one trip.
“While the lifts weren’t working we had been advising passengers to travel on to Lancing, which has step-free access between platforms, and return to Worthing.
“We would not expect passengers to pay extra, and apologise further to Ms Hopkins for any confusion.”