This is the reason why I don't start diary here.
Using my authors' society's rates for reproduction on social networks as a reference, for a profit-making organisation, and taking into account that the Facebook page has 2.6K followers, if they had come to ask for authorisation instead of taking photos from here, I would have proposed a flat fee of between €107 for a single month and €304 per year.
But when they don't ask for permission to reproduce, which is an infringement of intellectual property rights, I double the flat rate.
And since they haven't mentioned the Author's name or pseudonym, which is mandatory, I double this amount again.
In the end, if I were you, I'd send a bill for €428 for the month that the photo was illegally reproduced, as compensation. If they don't pay, or worse, continue to use the photo illegally, I'll take legal action.
Anyway, yet another seed company on my boycott list, and good luck to you. ><