The company increased the minimum price for people using phone boxes with a bank card from £1.20 to £6.50.
However, BT has now scrapped the hike, which came into force on 6 January, and said it would refund any customers who paid the increased rate.
Ofcom, which raised concerns with BT, has welcomed the reversal.
The price increase only applied to customers using a credit or debit card, with the cost of making a call using coins remaining at 60p.
Stephanie West told BBC Radio 4's You and Yours programme she had phoned a friend several times from a payphone at a train station using her credit card.
Source: BT
She later realised she had been charged £6.50 for the calls, even though two went straight through to a voicemail.
She said: "I would have used coins but the payphone wasn't taking coins at that time so I made several credit card calls and then when I got my bill each one had been £6.50."
BT has said a "very small number" of customers were charged the increased rate and said they would all get a full refund.
The increase was made after prices were reviewed, the spokesman for the firm said, but said the process of updating price lists inside individual phone boxes had only just started when the decision was reversed.
The spokesman said: "BT has recently reviewed the proposed increase for a credit card call from its payphones and decided to cancel this price rise.
"Although very few customers would have been affected by the proposed rise, Ofcom expressed some concerns about the increase, and we reviewed the matter.
"Any customers who paid a higher price since 6 January will be automatically refunded."
A spokesman for Ofcom added: "Ofcom had raised concerns about the increase in payphone credit and debit charges directly with BT.
"We are therefore very pleased that BT has reversed its decision."
BT has reversed a 400% price hike for customers who use public phone boxes with credit or debit cards following concerns from Ofcom.