Tried another AccuCheck/Pepsi deal at another Walgreens, but that didn't work out. They wanted to only give me $4.99 on my MQ after taking off the $5.00 Wags Q...I said Nahhhhhhhh don't think so.
On another note, I heard from the Manager at that Wags I had trouble at Sunday. He apologized that she didn't know the coupon policy and said I shouldn't have trouble again.
So there you go - if you know you're right, you don't have to take being treated like an idiot by these people.