"Outlander" and "The Spy Who Dumped Me" star Sam Heughan felt terrible.

Due to his constantly changing work schedule -- he's about to start shooting the action flick "Bloodshot" with Vin Diesel in South Africa during his Starz TV show's hiatus -- Sam had to cancel a scheduled appearance at the Wizard World Chicago fan convention on Aug. 24.

Marion Curtis/StarPix for LionsGate/REX/Shutterstock

So to make up for it, he spent five hours in the kitchen of his apartment in Scotland -- that's apparently where he had the best Wi-Fi reception -- Skyping with fans at the con to make up for his absence, news sites including OutlanderTVNews and CarterMatt TV reported.

Wizard World also posted a few videos of Sam's conversations with his fans on its Facebook page.

Though many praised the British actor for his devotion to his fans, some were miffed and lashed out at him on social media. Devastated, Sam hit back.

Casey Crafford/HBO/Kobal/REX/Shutterstock

"We tried to make it work," he tweeted. "Why I spent 5 hours Skyping from my kitchen. How many other people are willing to do that? I was excited and disappointed too."

A few online commenters also took issue with Sam sharing Instagram photos and clips of himself participating in (and winning) a dragon boat race with friends from his Scotland gym the following day. "Like is he serious right now?? This makes it look like he had no intention of actually coming here and isn't he supposed to be on a plane to SA? This is so tacky," one critic tweeted, while another added, "One would think he could stay off sm for one day to not rub it in even if he is leaving at night."

The actor -- who's developed a rabid fan following since taking on the role of Highland warrior Jamie Fraser on the critically acclaimed "Outlander," which debuts its fourth season in November -- was hurt and actually replied to them. "Reeally? Wow," he wrote.

He then reiterated why he couldn't make the convention as well as why he shared video of his last day in Scotland. "As I explained before, my schedule changed countless times. Supposed to leave last week. Then yesterday. Now, I leave for [South Africa] in the early hours. I'm sorry I was out enjoying my last day in Scotland. Your understanding is appreciated. What else do you want?" he tweeted.

A slew of fans jumped in to defend and praise him, and Sam thanked them for their kind words.

Earlier in the month, the actor and "Outlander" co-star Caitriona Balfe -- the Irish actress who plays Claire Beauchamp Randall Fraser on the sci-fi action-adventure show that's based on the bestselling historical-fiction book series by Diana Gabaldon -- missed another fan convention, this time in New Jersey, due to their filming schedules (Caitriona is shooting "Ford vs. Ferrari" with Christian Bale and Matt Damon). In Sam's case, he was also unable to legally travel to America at the time as his documents were being prepared for his "Bloodshot" international shooting commitments.

"In response to comments re NJ, fully understand disappointment," Sam tweeted at the time, responding to disappointed fans. "I was excited to attend when I signed up but then got new movie offer. We asked for them to clear dates but due to various changes it has been unavoidable. I also have no passport at present due to visa office."

On Aug. 26, Sam posted a video of himself at his Scotland gym on his Instagram Story (he's had to further bulk up for his role opposite Vin) with the message, "The last early-morning pre-flight session... next stop, Capetown." He also posted a clip of his plane taking off. "Goodbye Scotland ya beauty," he captioned the post.