Replacement parts for arlo camera mount

[RCaver]

I mounted my Pro 4 camera using the anti-theft mounting system to a tree. A year later, that tree is slightly larger and broke the back mounting plate and the mounting ring that attaches to the plate. Those are the only two parts I need but I can't find any help from Arlo to purchase those items without spending $50 to replace the entire anti-theft mounting assembly. And I can't find a support phone number anywhere to call and talk to them. Any advice is welcome.