Coffee crunch

Every morning at work I refill my Dunkin Donuts coffee mug at the goverment complex Subway/DD location. The manager there has always cut me a bit of a break, only charging me a buck for the refill instead of the $1.23 it should cost. We always were friendly and it was just a nice little perk. When I went to pay for it yesterday, I had my dollar out and ready and she says $1.23 with a slightly annoyed look on her face. I mumbled something about inflation and surprisingly pulled out another buck. I am unsure why she decided to raise the price for me. For some reason it bothers me a bit although in reality in means little more than an extra $1.15 a week. However in practice, it normally winds up costing me and extra 5 bucks cause the change from the transaction gets thrown into a drawer so my wallet gets substantially lighter than one would initially believe. It would be too uncomfortable and odd to ask her why she decided to raise my price. Perhaps I offended her somehow, maybe someone else said something to her about my preferrential treatment. Today I even threw the 77 cents change into the tip cup. Maybe that was the issue, the even dollar transactions meant no tip. After I did it, I felt stupid for caring if the dunkin donuts woman was pissed at me.