Burger King complaint: Refused to take my coupon

I went to the BurgerKing near my home today and ordered two chicken sandwiches with two fries with a coupon I had printed online. They refused to take the coupon and charged me full price for my order. So instead of paying the coupon price (I get the coupon flyer in the mail all the time but couldn’t find it so I printed the one online).  I found this to be bullshit and had to pay an extra $9.00 for my order cuz they said they cant take a printed coupon…when in fact where I got the coupon it said PRINT THIS COUPON at the top of the page.  I’m sick and tired of getting ripped off (SEE attachment) SO I’d like my coupon honored please and a refund.It was the Hopkins Knollwood restaurant 
My name is Tim Marx, you can email me back on this issue please and let me know what we can do about this. I read the reviews on this place after the fact and there is not a very good rating and LOTS of complaints on this store and many others. What’s the problem??? 
If you need the receipt i can scan it and send it to you but its out in the car right now but i can get it. 
I also ordered a medium chocolate shake with the order. So from $10.79 (approx) with coupon I was charged almost $20.00 for my order…