McDonald's

I drive thru ordered today at lunch time a trio big mac, a trio mc chicken, a trio mc croquette and an egg mc muffin for me and my colleagues at work. Arriving to work, we found out that an egg mc muffin is missing so we had to share what we have. After finishing the meals, I drove back to Mc Donal and asked for a refund. The manager refuses to refund and the only option is for me to get the egg mc muffin. I argue that I have to go back to work and we all ate already but the manager does not li