Which file to edit these words?

Hi all

I want to edit some terminology and fonts inside my listings template. I am using the Responsive Coupon Theme. The problem is I can’t find the file where titles are.

See the attached screenshot. The font for the expiry date is too small and I want the change the call to action Visit Link Here to something else and make it bold and more obvious.

What the File plugin tells me it’s single.php but I can’t find it in there. Anybody any idea where I can edit this?

Thanks
Jasper