Guys, how to check late night internet balance with this new package?

"Add on bal" to 28882 doesn't seem to work for me. "Max status" also doesn't work.

I got "Sorry we're unable to process bla bla bla..." but I think I still got at least 5GB left of internet burung hantu. I can still use the internet just fine but can't check balance.

I haven't top up the internet since the new price came out since I don't wanna get burned on my leftover burung hantu balance.

Anyone know how?