Tim Hortons review: extremely poor service.

Good morning, I have a concern with the tim hortons on windmill road, we work at a car dealership local to this tim hortons, we do a lot of business (12-15 coffees and donuts daily), the concern is each and everytime the order comes back wrong, not just one wrong thing, but today there was 5/13 coffees wrong, and this is consistent, we also notice that there is one cashier who is extremely rude, we think the orders are purposely mixed up because of the rude way we are served, I myself buy 3 coffees a day from there, but will go to the mcdonalds moving forward, as will the car dealership based on crazy poor service.