The Southwest Airlines Companion Pass is a remarkable perk for loyal customers. Last week, however, thousands of Southwest customers who received emails from the airline saying they had earned the pass sadly found out they actually had not.

The Companion Pass -- which allows a designated companion to join you on any Southwest Airlines flight for free, paying just taxes -- is offered to Southwest customers who earn 110,000 Rapid Reward points or take 100 qualifying one-way flights in a single calendar year.

You don't have to be a math expert to know that that's a lot of flying.

Alternatively, the airline offered a Companion Pass earlier this year to people who signed up for the Southwest Rapid Rewards credit card and charged $4,000 on it within a certain period of time (sorry, that alternative has expired).

Long story short, the Companion Pass is a perk highly coveted by Southwest customers, but it isn't easy to get.

That is, until thousands of Southwest customers received emailed notices last week that they had been awarded Companion Passes. Excitement reigned supreme as excited customers got onto social media to trumpet their tremendous good fortune.

As Rebecca Momany said in a tweet,

You know it's going to be an EXCELLENT day when you wake up to an email indicating you've earned your 1st @SouthwestAir Companion Pass!!!! Someone check on me... I might have died and gone to Travel Bug Heaven.

There was just one problem. Those emails from Southwest were a mistake. A really big mistake. The customers had not actually earned Companion Passes.

Confused customers got back onto social media to ask Southwest if they had or had not earned their coveted Companion Passes. The answer? No go. In one response to a customer via Twitter, a Southwest representative said,

We hate to break the bad news, but this notification was sent in error. Our Marketing Team is working on having this status reversed for our Customers as soon as possible.

Of course, first receiving Companion Passes and then having them yanked away did not make the affected Southwest customers particularly happy. In fact, they were downright angry. Tweeted another customer,

Hey @SouthwestAir I got an email saying I achieved companion pass only to check my account and find that was not the case. Huge disappointment.

While it's unlikely that Southwest is going to give thousands of people free Companion Passes as a result of their mistake, I'm looking forward to eventually hearing how they decide to make up with their disappointed customers.