This issue of entitlement is great. There are a lot of good comment and mostly thoughtful.
My main issue is if you offer a loyalty program you need to train people on the benefits to your customer. The whole idea is to encourage long term loyalty to your brand.
If you do not provide what you offer is where it can hurt your loyalty form the best customers. Remember the company elected to offer in in exchange for our continued business.
I feel the best comment is to try and always be polite and you will usually get more from the company.
They need to remember why the program is offered. It is not a free gift as some uninformed employees state, but an earned benefit offered by mutually accepted terms and conditions.