How to get the $20 add on unlimited tablet plan through Premier?

Good evening I have an ATT premier account and am having some issues. I have a few tablets on my plan and want to add more through Premier. I was told by a rep its good to create a new group each activation that way it doesn't affect the 10 main lines that are meant for phone lines.

But the issue i'm having. When I create a new group in premier during my activation, the tablet plan i Need doesn't show up. The plan is " AT&T Unlimited for Tablets $20 "

When I call in every rep has nailed it they can create a new group and put that plan in no problem.

I can add it to my existing business your way plan and its the same $20 BUT it takes up the 10 lines in my group and the activations haven't been going through they are just stuck on submitted. I have to call in to have the order placed. I have provided MY tablet IMEI and my brand new sim card every time. Once I call in they activate immediately.

Maybe someone has some tips, I just don't want to call in or go into a store every time I need an activation done. Is there another site I can use that is newer than the Premier site.

Looking for any info, thanks again.

(Link to the Plan)

https://www.business.att.com/content/dam/businesscenter/pdf/legal/att-unlimited-tablet-brochure.pdf