Dollar Tree complaint: Really bad Customer Service From Manager (Disney)

9182021 this evening I went into The Dollar Tree around 630 and had the worst experience, I have ever had as a customer in my entire life. I went into the store to get a few things as birthday gifts, when I got to the checkout I asked the cashier to put 10.00 on a gift card. She in turn told me that she could not do it and that she needed to have a manager to do it. So the next step, she called the manager (Disney) and I waited, she(cashier) then asked me to pay for my purchase I told her that I wanted to pay for everything at one time so she called the manager again (Disney), well after about 5 minutes waiting for Disney to come up front to put 10.00 on the gift card, she finally appears, she walking up the aisle with register tape in her hand and talking on her cellphone. Well this is when I was treated like I had two heads, first the cashier tells her that I wanted to reload a card, (Wrong)..I said no I want 10.00 added to this gift card, Disney proceeds to say …well I can do that if you take your debit card out of the machine, I tell her that I don’t have my card in the machine, Disney then tells me yes you do…and I don’t need to have an attitude about it, at this time no attitude was no where in my person all I wanted to do was get my gift card loaded so that I could get out of the store and on to what I needed to do, in the mean time Disney told me 3 times that I had an attitude and that she was the manager and that she did not have to wait on me. At that time I told her that she was right…that she didn’t have to wait on me and that I did not want any of the merchandise and that she was being very rude because I am a customer and you are the one with the attitude and that I was being treated very wrong and that I will be contacting her higher up her response was do it I don’t care. So here is the first of many letters.
I work in customer service, I have worked in HR as well and this is no way for a manager to act toward a customer especially when the customer was just trying to buy a 10.00 gift card. I had no attitude when she stated I did..the attitude came when she treated me like I was not a paying customer.