I think your are completely wrong. As I read their reply, if you had not installed it after 30 days they probably would have let you exchange it. Had you filled it with coolant within the 30 day period and found it wasn't correct, they would have let you return it. But in your case, you used it and were outside their return period. Here is their return policy.
"Everything we sell is returnable for full part cost credit within 30 days (except certain special order and discontinued items identified in our catalog as "No Return").
If you're not satisfied with something or you just decide you don't need it, you can obtain return instructions using our Order Status & Returns page or by sending e-mail to
[email protected] (in your email, please tell us your order number, the part number and the reason for the return). If a part doesn't fit, don't try to "make it fit" and risk damaging the part or your car (or yourself). We won't accept responsibility for any costs exceeding the cost of the part (and you don't need the aggravation of doing a job twice!) so please inspect the part before you start the repair."
It sucks for you but they really are easy to work with and well worth the few days it takes for shipping. In many cases, they used fedex and I have gotten my parts on Saturday.
