Why Do I continue To Shop There?

I hate the local Toys R Us. There is always some sort of problem when I shop there and their customer service sucks. They are obviously not taught how to properly deal with customers. I had 2 coupons that I printed from the internet. One was $5 off a $25 purchase, the other was 20% off a clothing item. Both said they could be used in combo with other coupons. So I spent a good hour trying to find a dress for Cameron for a beach side wedding and some summer clothes since it's in the 80's where we are going for the wedding. I found a darling dress and one outfit. The rest of the spring/summer toddler clothes were dreadful. I picked up a toy and some m&m's as well. The $5 coupon went through, but she was having trouble with the %20. She was the only register open, long line behind me and we are waiting for someone to tell her how to put the coupon in. Turns out I can not use the coupon because there is no bar code printed on it. The manager tells me I am "missing the bar code" and that I "didn't print the whole coupon." The instructions on the site told me to right click on the picture and print, which I did on both. I realize there is no bar code on it, however why does there have to be one? Can nothing be entered into the register with out a bar code? Is it not possible to view my highest priced clothing item and manually take off the 20%? I strongly feel this falls along the lines of cashiers who will not key in a credit card number if the card doesn't swipe. The coupon specifically states the conditions and expiration date and it will put in the drawer with other coupons. Is it golden law that they can not manually do the 20%? I told the lady I didn't want any of what she rang up. Not because I was angry, but because I really didn't want to purchase the dress with out a 20% coupon and with out the dress I didn't have enough to use the $5 coupon.
I went back home and checked the internet again to see where I might have went wrong. After some searching it appears that the coupon site offering the coupon just posted the picture they got from the actual TRU site. You should be able to click the picture and that will take you to a coupon with a bar code. I still miss out though because the page with coupon has expired. I suppose because today was the last day to use the coupon. I wasn't able to find anymore coupons online so I suppose I will have to pay full price for the dress. Why couldn't they have just typed it in.