Business Profilefor39dollarglasses.com

I ordered some glasses in July and received them 7/31. They had a manufacturing defect (2 machine cuts on each side). They were metals glasses and these cuts were not meant to be there. I requested a return 8/27 and they sent me return instructions 8/28. At that time I thought I had started the process correctly and sent in everything, following the instructions on the email and return form. It was sent out 9/7. I spoke to customer support today 9/20 and they let me know they received the item and that I got store credit. I want a refund back to my card. They state that the return must be post marked within 30 days. One, I have to wait for a response before being able to return and two, they don't list that requirement on their return response or documents (attached). I received the email and followed the directions.I then asked for a manager but they never replied back. I've also requested a transcript of our chat but they won't send to me. (Copy paste word doc attached)If they had let me know that it needed to be postmarked by 8/31, I would have but they left out that very important piece of info, I believe purposefully, so they would not have to refund. I don't mind the idea of store credit but when it's an issue of improper manufacturing and defective product, why would I want to waste my time going through this again?