Problem with SunFrog Shirts Stripping Affiliate Links (Sales)

I've recently decided to switch from using Teespring to SunFrog shirts for some of my campaigns. I've been doing this now for about a week and have noticed a couple of times where I'll upload a design to the site, get the affiliate link, and then post it to my social media sites. I'll check back later (often within an hr or two) and I will have several sales but am only receiving an "artist's" commission for the sale (roughly $1) instead of both the artist's and affiliate commission ($6-7).

I get that there is a slim possibility that someone lives on the SunFrog shirt site and every time a new design is posted they take the design and send it too their lists. Or, that several people coincidentally find my recently uploaded designs and choose to buy multiple shirts within an hour or two of me posting them. However, I think what is actually happening is that somehow my affiliate link is getting stripped somewhere and I am not getting the affiliate sale credit. I have contacted SunFrog and asked for some type of documentation showing that these sales did indeed come from an affiliate. I got the following formatted response

"We have a huge amount of traffic that is driven to our site via approximately 40 different pet sites. Each of the end users are doing searchs on our site so I have no doubt that these sales are credited to an affiliate."

This tells me that they either A) do not care enough to do some basic research to verify that their system is potentially stripping sales, or B) are willfully stripping sales from affiliates. Has anyone else had any issues like this with Sunfrog? Are there any other shirt suppliers out there that people are having success with besides Teespring and Sunfrog?

Thanks WF!