Have you checked self serve if you still have data left this round due to proration? What is your billing cycle?

I alreadt checked it...

I usually pay my bill on the first day of the month.

Right, but your billing cycle is from the 28th (yesterday) till the 27th. You should definitely be good for data now :)

Can you try to reboot your phone? What phone is it? Is there anything else that you did when you changed plans which might effect your data?

Silly question, but was your data working prior to you changing plans?  Like did you have a data plan previously that you actively used?

Wow..Thank you so much for your kindness. :)

I solved the problem. I was an Idiot.

Have a good weekend. Thank u.

I solved the problem thanks to Sophia who gave me the answer. As you know, It was silly question.

Anyway. Have a good day.