I am in California and work for a Dr's office. We have a patient who is discontinuing care with us, and has a balance due. The patient asked if she could pay it in 2 payments, one immediatly, and one in 2 weeks. The Dr. said we could hold a balance for her, but we would be charging her interest of 15%. The patient never signed a contract, just has a verbal agreement with the Dr. to make certain payments. No interest was ever mentioned. Is this legal?