Bite & Repeat accidents?

I just got bit on the thumb by a 10lb lhasa apso while trying to crate it after it's 7th accident in my house since getting dropped off this morning. The bite is very deep with bruising under the nail (not captured in picture).

Before agreeing to book with me, I established that the first 4 accidents are on the house after which it's $10 additional if on floor and $30 additional if on furniture. I wrote this up in the notes from our meeting that I documented in Rover. They agreed.

I've alerted the owners with every accident and the bite along with pictures. I've since crated the dog to let it calm down before taking it for a walk once trust was reestablished.

I called my doctor, started antibiotics and got a tetanus booster. Owner says that it has rabies vaccines up to date. I will ask for proof of vaccine when they return home.

How would you handle the situation? Any other suggestions? Is it reasonable to charge for the bite? Moving forward, should I have a policy for bites?

Thanks for your help!