Step 1: talk to the neighbour
A polite conversation often resolves the issue. Some drone hobbyists are unaware their flights attract privacy concerns.
Step 2: file a Transport Canada complaint
Transport Canada can be contacted about unsafe or illegal drone flights. Commercial drone operators require certification and must meet specific rules.
Step 3: consider a civil privacy claim
If recording captured identifiable images of you or your family, you may have a claim for intrusion upon seclusion in Ontario or similar torts in other provinces.