Tim Hortons review: Pocketing money

Everytime I go to my local tims and use change they keep my change from 5cents to a few dollars I have to asked them for my change, yesterday I ordered a small ice cap I asked how much he told me 3$ I went today and used my card it came to 2.30$? I know its just change but I find disrespectful when they pocket my change without asking first if I want it