LONDON — When British Airways told scores of customers on Friday that their flights in September had been canceled because of a planned strike by pilots, then hours later told many that never mind, there had been an “error,” travelers’ fury poured out.

The airline received 38,000 calls in the first 24 hours, and the confusion generated 33,000 tweets during the same period. The airline said it had to increase its Twitter customer service teams by 20 percent and add 70 extra staff members to take the calls.

Many enraged customers said they had already made alternative travel plans before being informed that their flight would, in fact, go ahead. Others said that when they tried to call to get clarity, they could not get through to the airline’s customer service representatives. So they took to Twitter on Saturday and Sunday to vent.

“Disgraceful service by @British_Airways,” Dean Walton said in one post. “Canceling our holiday, then, after we booked alternative flights, they have now emailed saying the original flight isn’t canceled after all.”