Still receive refill reminder after refilling my account

Hi,

I refilled my $60, 3GB prepaid plan in one of the T-mobile store on Sunday (Oct 19) and the due date of payment of my plan is Oct 24.
But, I still received the reminder (on Oct 22 and Oct 24) telling me to make a payment call to avoid any break in my service.

May I know is that normal or is there something wrong with my refill action on Oct 19?

Thank you.

Cheers,