Merchant sent item in wrong color

I order 2 pair of leggings one black and one gold. I received both in black. With this merchant there is no way to verify color choice at check out. I called and all the company is willing to do is say "I'm Sorry". I told the customer service rep, Autumn that this had happened to me before and I accepted the error. I told Autumn that I was a frequent customer and I spent over $600 in the past month. I told her sorry was not good enough and that I would discontinue my online shopping with their chain of stores.