Poor service and Rude

I was paying my account April 05th and Amy was very very rude towards didnt have change and she insisted that she cant help.as why because you dont have change how can that be my problem worse after lot of arguments she gave coins told can please have a plastic and her answer we dont felt like i wasnt welcome in store I demand her personal apology in writing from her . she doesn't deserve to be at forefront dealing with customers.