I purchased a coupon, but Stackcommerce gave me a ...

I purchased a coupon, but Stackcommerce gave me a faulty coupon code (didn't work on the website). I sent a ticket, and received a (very slow) response with a new code. However, when I went to the website to redeem, there was no place to input the code, so I was charged for the full price of the product AND charged for the coupon. I have been trying to contact Stackcommerce for the past MONTH and have thus far only received two (very unhelpful) responses. I highly do not recommend this site to anyone. The customer service is extremely disappointing.