Most food companies are cautious when it comes to complaints.
I'm not sure what you expected the company to do, but they have to look out for themselves first.
- People make up stories all the time to get "compensation/reimbursement". Best case scenario is if they sent out a complimentary jar of their food, but for a small company that doesn't make sense for a random manufacturing accident.
- When larger animals are processed into smaller particles, it's never 100% unless they run the "batch" through the machine several times. Chunks of flesh/bone can escape the "processing" depending on the operator. It's not unusual at all.
- The type of salmon that Omega1 uses in their products are probably trout sized since they are cheaper and there's less of a human market for them.
- Bettas in the wild, eat small fish, amphipoda, worms, insects & near microscopic critters in the water they're spawned in.
Where in the WORLD would a betta find Salmon, Halibut, Rockfish, Krill, Shrimp, Seaweed to eat in these same bodies of water?
Bettas are smaller than a pack of gum/lipstick. So if you're going to feed them a food product made from a larger animal, bone fragments are one of the risks you'll have to accept.
Just be more careful and give the company a break. It's an accident.
Nowadays you can't even apologize because an admission of guilt via email, opens you up for a potential lawsuit.
Stick with pellets since the portions are easier to control than flakes.
BTW, the bone from the first picture looks like a pin bone. It's the most common bone you'll choke on from a salmon/trout/artic char.