Some BT customers have complained they were pushed into their overdrafts after being charged twice on a recent bill.
BT has admitted that a "small number" of customers had a "duplicate direct debit taken from their bank account" and has told Mirror Money that the issue has now been resolved.
The group did not confirm how many people had been affected by the mistake or which payment dates were impacted.
The telecommunications firm said it has contacted all those who had been affected and have issued them an automatic refund of the overpayment.
BT says the refunds should already be in the affected customer's bank account.
The billing error was highlighted by MoneySavingExpert.com after the website heard complaints from several BT customers.
One Twitter user @loose 167 tweeted BT saying: "You’ve charged me twice and now I’m in my overdraft. Happy Tuesday"
Another Emmew10114 said: "@bt_uk how long for the refunds to be sorted where u have charged customers twice this month. Mine is £60 it’s a lot of money to be down I need it thanks.
The Money Saving Expert website recommended BT customers "take screenshots or print out statements detailing any errors" and record any late fees of charges they have had to make if they have been unable to pay as a result of the duplicate payment.
BT has told customers who have been pushed into their overdraft or have been hit with late fees to contact the firm's customer service team.
However, it did not confirm whether it would compensate customers in this situation but it did say it would "discuss" the issue with them.
You can contact BT either online or over the phone, their website lists the particular numbers you need to ring for each service.
You can also complain about BT using the free complaints tool Resolver.
BT shared a statement about the issue on it's website which said: "If you’ve experienced a duplicate Direct Debit for a bill you’ve already paid, please be aware that we’re working on fixing the issue now and it should be automatically refunded shortly.
"We apologise for any inconvenience this may cause."
