In terms of compensation, BA said they would be in touch with customers "and will manage any claims on an individual basis".
IAG said the data breach had been resolved and the website was working normally, and that no travel or passport details were stolen.
The airline has taken out adverts apologising for the breach in Friday's newspapers. The air carrier also recommends affected customers to call their bank and follow their instructions, to minimize potential financial damage.
Another BA customer, Stephanie Jowers, said she contacted the airline hours before the hack was announced to query a suspicious charge on her account but was not informed it could have been compromised. Probably won't get it back before we fly (ironically).
Gemma Theobald said she had booked on Sunday and only found out about the breach on Twitter. "Couldn't do anything other than cancel my card... not how I wanted to spend my Thursday evening". To have your customers' financial information stolen by unidentified hackers.
Watch Protesters Swarm Sen. Grassley’s Office Before Kavanaugh Hearing: ‘These Are Fascists’
Booker then admitted he was in violation of the Senate rule Cornyn had called him on, which allows for expulsion from the Senate. He called it "a moment of judicial independence where I think the court came together" in a unanimous decision.
It was not immediately clear how many people were affected by the data breach.
A spokesman for the Information Commissioner's Office said they would be making inquiries about the data theft. We are deeply sorry for the disruption that this criminal activity has caused.
Some 75,000 passengers were left stranded after a glitch forced the airline to cancel almost 726 flights over three days.
This is not the first customer relations problem to affect the airline in recent times.
The Guardian reports that 380,000 "payment cards" were affected.