Southwest Airlines took to Facebook keep customers informed after a computer issue resulted in customers being charged multiple times for a single ticket.

Ironically, Southwest held the half-price sale on Aug. 3 to celebrate a Facebook milestone: Its page has garnered 3 million “likes.”

Initially, Southwest referred to “site performance issues” due to an overwhelming response to the promotion and promised to correct “duplicate bookings.”

But for many customers, the situation was far more serious.

In some cases, customers who used debit cards discovered that their bank accounts had been wiped out at the start of a weekend.

St. Louis Circuit Attorney Jennifer Joyce told a local television station that she used a debit card to buy tickets for herself and her husband and was charged for 30 flights, to the tune of almost $5,000. A Denver woman said she bought one ticket but was charged $9,000 for 35 flights.

“First, we want you to know that we are working to identify duplicate bookings and charges and are proactively canceling those additional reservations, actively processing refunds to the Customer,” Southwest said on its Facebook page, adding that it had called in additional staff to resolve the problem.

It said customers who used debit cards and received overdraft fees as a result of the additional charges should fax documentation of the charges to the carrier.

But the “proactive” canceling of flights also knocked out the flights that customers had intended to buy, according to several customers who took to Facebook to complain after experiencing long hold times when calling the carrier.

Southwest then instructed employees to restore the itineraries, honoring the original fare.

One debit card user noted that Southwest was refunding the charges, which could take several days, instead of reversing them, which is often a quicker process.

On the following Monday, Southwest reported that “all erroneous bookings have been identified and refunds are currently being processed for all Customers impacted with duplicate bookings.”