Property management company underbilled tenant.

[Susan King]

My husband and I own multiple rental properties. We've been using the same property management company for 10 years, so I guess we trusted them too much to go over our monthly statements closely. I just discovered that they've been under-billing one tenant nearly $350 a month for like 10 months. My guess is that it's one billing person's mistake and we caught it too late. And the tenant was just silently happy to pay less. Who is responsible for this and is our loss recoverable?