Why am I so worked up about this?

It was after 8:30 and I was making the baby's last bottle before bed. I noticed that I was extremely low on formula, something that I usually do not let happen. I mean, if I have a coupon for it and it's on sale, I buy it.
Anyway, I sent my husband, Matt, to the "to remain unnamed" store to grab some with the intention of visiting my normal stores (BJs or Target) later in the week. I sent him armed with 2 coupons...a store coupon for $2 off and a manufacturer coupon for $1 off...I also had given him a register printout coupon for $2 off any purchase. (sometimes I think that he is a little embarrassed with all the coupons)Therefore, a grand total of $5 off.
He shortly returned and stated that it was a "fiasco" and that the store only took the $2 store cash coupon. How could they not take their own store coupon or the freakin' manufacturer coupon? Those manufacturer coupons were sent to me DIRECTLY from the company after a strongly worded email was sent to them regarding the lack of coupons I had received after the birth of my 3rd daughter. Hey, I had used the same formula for all 3 girls...since 2005. I didn't even blink an eye with their recalls...my unwavering loyalty deserved some damn coupons.  Long story short, the very nice customer relations lady emailed me back and promptly sent me a sample and 2 coupons...I was enraged with only 2 coupons but thought it was best not to press my luck with another email.
Back to the situation at hand...it really BURNS ME UP when stores give you crap about coupons. You put them out there, expect people to use them. Using a store coupon and a manufacturer coupon is perfectly acceptable.  And for the record "to remain unnamed" store, you are lucky that it was my husband and not me there tonight.
So as I write this I again ask, "Why am I so worked up about this?"... really. why? 45 minutes later and I was still fuming about it. Is this what my life has come to? Oh well. Hopefully I can get over it and force myself to finish this glass of wine.