How do I unblock a link to my facebook page if it's deemed unsafe?

I’ve been trying to set up a facebook page for my online store but apparently facebook has blocked me from posting a link to my store at teespring.com.
I’m not sure why, it claims it’s unsafe but it’s not unsafe. I just simply copied and pasted the url onto my page. Is there another method that would work?

I’ve let them know but pretty sure they won’t reply. How do I resolve the blocking issue?