After turning in my stack of 55, I ran the elements again and turned in the 3 I got for 3 certificates + 12 wind elements. I submitted a ticket and hopefully I can still get the other 220.
I actually carefully planned this so that I could have a newborn AND a legendary so that I could use both the 20% xp/tp/drop rate, and one of the legendary pet buffs (likely the 10% quest bonus with my new dwarf alt, and the -10% damage on my 72 warrior) in the same day. It was so disappointing thinking I would have my legendary pet today, and having this bug happen, but hopefully they can fix it

My main is only another day away from having enough for newborn + legendary, and now I know not to turn in so many at a time. I don't love the idea of running back and forth from the element guy to my bank box a few times, but I can deal with it. I'm sure it's just something they didn't think all the way through when they implemented the zodiac pets - like how there hasn't been a Cancer pet, or how you can't put increments of 3 elements in your transmuter, you have to just do 3 at a time.