Really disappointed by ShopBop online store

I wanted to use their 4th of March coupon code on my dress that I planned to buy many weeks ago and waited for the real deal. I was so happy to read that ShopBop had a 4th of March coupon code that would take off at least $15 on my purchase, but unfortunately the story took another turn:
The coupon code had an expiration time which was March 5th at 12AM CST . I placed my jeans in the cart but as I wanted to check out @ 11pm CST March 4th the code already didn't work anymore :-(
Shortly after 11pm CST I wrote to ShopBop an email explaining the problem but the woman at the customer service just didn't want to believe me (even though the time of my “non-purchase” was on my mail as a proof that I didn’t overlap the deadline of 12am CST) and she didn't want to help me further. I wrote her another email to explain the situation once again but it seemed that she didn’t really read through it and treated me like a liar.
This problem left me really cold and I am really disappointed by ShopBop online store and will really think about buying from them ever again!! I had better turn to another shop like fsession.com as my friends recommended.