Affiliate links redirecting

We manage a blog and have a post using uniquely tagged links for a client that just published today. All of the links are correctly input in our CMS, but when the links are clicked on our site, the tagging structure completely changes (to some weird affiliate tagging).

Can anyone help me figure out how to fix this? The tagging provided by the client is important for tracking the success of this campaign.

Here is the post:

All “overstock” links should go here:

but on click they become this:

Thank you in advance!