Why would they send you to a http at all if they already have https. This just seems like complete incompetence. It’s not like they have an excuse like their ad networks don’t work with https.
But don't worry, they'll have an engineer approve it next time as well!
So, how did they copy an http url instead of https because they website should have redirected them to https before processing the request (and I just hope that their internal network isn’t compromised).