Extreme couponing wtf?

Well it has been awhile hasn't it? its been a bad two weeks for me really, I am typing currently with a healing broken hand, and a healing scratched cornea in my right eye. I have been kinda out of commission for the internet, Yet I still had to work. Today on my first day off in awhile and not injured too badly I made it my mission to attempt this couponing thing I have been seeing on Television. Last night after returning home from work, watched an episode of this show Extreme couponing and started looking online, my wife informed me of a website called southernsaver.com and I really had to go on help from my wife since the show its self does not show the store names, or the websites where they get the coupons or how they get so many.
found a deal on this website at CVS Pharmacy for 5 for 5 on floss, tooth brushes, tooth paste and a few other random soaps. Then they show a printable coupon for reach brand floss a dollar off, and coupons 2 dollars off two reach tooth brushes, I print off enough of these coupons to get 4 packages of floss and 6 toothbrushes, this should be two of the 5 for 5 deals, for free.

At the store, there were 4 floss packages, and no toothbrushes, so we attempt going to another store, other store there is only one package of floss. In the end we go back to the first store, get the 4 packages of floss, no toothbrushes, and a bottle of Listerine that was included in the 5 for 5 deal. my total? It should have been 1.08 by my logic, a dollar for the item I did not have a coupon for and the NC state sales tax for that item, No the total was 1.40 I paid sales tax on 5 items, 4 of which were free. I was taxed by the state for something that was free, do help me understand this?