Tim Hortons

I frequent this store often and typically purchase a medium vanilla ice coffee. Today I did the same and the size of the coffee I received was very small. I inquired if the coffee sizes changed and I was not answered, but assured what I received was a medium. If the size I received is truly the "new" medium size cup, I will no longer be frequenting your store, but go down the street to McDonalds and get a normal sized medium ice coffee. Please advise. If the size I received is not a medium vanilla ice coffee, I would like to be compensated. I used the first half hour of my work day typing up this complaint as I was not able to get anyone to answer the phone at the store in question, which is quite frankly unacceptable. Thank you!