The Police can't go in, they'd be attacked and badly hurt. And I know, where does that leave law-abiding citizens, but the police are people's dads and husbands too and should be able to go home at the end of their shift.
But you could go in, they won't hurt a woman. You might well have to buy Bella back, and yes, you shouldn't have to. But if you want her back.
I'd go in and ask someone who to talk to. Explain that you'd lost your goat, that you understood someone here had 'found' her and you'd be very willing to pay a reward to get her back as she was a pet, like a dog or horse to you. No accusations, leave a 'bridge' for them to back over.
I think you'll find someone will go and get the person who has 'found' her. Control your anger, be as pleased as if they had found her, name your reward, which may well have to be significant

Maybe about half what it might cost to buy her, hopefully the typical 'bird in the hand' attitude will win out.
Fingers crossed, I am gunning for you and Bella here

And then beef up security significantly at your place, you don't want more visits
