I just wanted to make a payment

Yesterday I picked up a prescription for my daughter. While I was at the doctors office. I wanted to make a payment. The reception says she can't figure it out. But than says she will send me to billing so they can explain what is going on with my account. I am like, I just want to make a payment. Now I am freaking out thinking something is really wrong. So, I get sent back. I tell the lady at billing the same thing. I just want to make a payment. But oh no she totals up everything I owe and wants me to pay the whole thing. I tell her I want to make a payment and re said the amount. I told her that is what I told the receptionist. The lady snaps at me and says she doesn't take care of it and repeats the amount. I told her I am making a payment of such and such amount. That's it. The billing lady goes didn't you have an appointment today. I said no. I was in here to pick up a prescription and wanted to make a payment while I was here. Do not charge me for an office visit when neither for my kids had an appointment. By time I left I was pretty peeved at the hoops I had to jump through just to make a payment. Oh and I only owe less than five bucks on all bills. So, when I my daughter has her appointment in a  couple of weeks..it will be paid in full.