We're a small community veterinary clinic. We're having problems lately with our pet owners not paying their accounts in full. It's a very small number of our clients, but their accounts make up a big chunk of our income. We have a system where they need to pay a deposit upfront before treatment, and then they can pay the rest over a certain period. We send them the bill every month to remind them, and we call them occasionally to remind them. Do you have any advice or experience in dealing with these types of clients?