Burger King complaint: Cost

Frist my family loves Burger King. We live in Oregon and we ordered 2 of the 2 for 10 meals. Cost us $20 bucks. Great price Great food Great service. We traveled to Petaluma California and went to Burger King store7410 and ordered the 2 for 10 meal deal and were told that they don’t have that deal they have a 2 for 12 so we ordered 2 of those. We love Burger King it’s not the money it’s the way the girl treated my son. My son is 30 but he suffers from autism he didn’t understand the extra charge and began trying to explain he became frustrated and the girl canceled his order and asked him to leave. A difficult situation all around. I went in and ordered and got our food paid the extra I told the girl that she could of just took my son’s money and then just told me that she need more money for the order. If prices are going to vary from store to store you could make customers aware.