Why is customer service really dead...

So we were at McDonald's the other day ordering McFlurries. I placed my order, an Oreo McFlurry, to the cashier. We had a coupon (women "b" shoppin) for a free McFlurry and I gave it to her after my order. My hubby was going to order his McFlurry, but she looked at the coupon and walked off. Eventually it was obvious that she didn't know how to put the coupon in. She didn't say excuse me for a sec or I'll be right back, she just flat out left! Eventually, a manager comes over with the worst look on her face. I'm expecting something from her like "I'm sorry for your wait or I'm sorry, we don't take this coupon", but instead she tried to put the coupon in. The manager then gives an ugly look and says "You gotta buy anova McFlurry fo dis coupon". I wanted to say "We know that, but your employee walked off and we didn't know what the heck was going on!" Instead, my hubby just placed his order for his McFlurry. The original cashier then made our orders, handed them to us and walked away. No thank you...come back to see us again, nothing! I can't believe that employees are no longer polite. A simple "excuse me or thank you" could go such a long way with a customer. Customer service is really dead!