Call 800.828.0228 and when somebody picks up, kindly ask to speak to a supervisor. If they ask why, let them know you just had a very upsetting experience and you want it escalated and noted. Then you can log a complaint with them. You can then follow-up with an email.
Not to hijack your thread, but just wanted to add this in....Guest Services does not always mean nicer people. I had to call today because they messed up on a credit to my Visa...the person in Guest Services treated me like I was really putting her out. She was very rude. I did not complain to a manger, but I let her know that this was a mistake they made and she should not treat me in the manner she was. I very politely and calmly told her I had every right to call and request they correct their mistake and her attitude was not necessary. She hung up on me.