Cannot even respond to opening a simple bank account

I tried to open and FNBy account for my kids in March 2021 online. I sent through countless documents everytime they request it. Now they want tax numbers for my kids, my kids are 3 years old and 1 years old, they dont have tax numbers. i just wanted to open the account for them linked to my account. Now they asking for tax numbers, where must i get tax numbers for them. Its now May 2021 and still trying to get it sorted.