Having been in this situation with a different species of critter, Inform your AC that
A its harassment.
B they can be held liable for following up and encouraging the harassment.
C.If your legal and they know this they have no reason to follow up on every call, have them demand from the caller, pictures, recordings etc.
D The harassing party can be held liable for AC reimbursement for travel time, gas mileage etc for every non warranted call out to your place.
1 trip is acceptable
2 trips for a follow up on original complaint is acceptable.
3 + calls from the same person is now considered harassment.
Pass the word to neighbors with intent of it getting back to the caller you are fully prepared to file harassment charges.
I will guarantee calls will stop.