i got some problem using celcom direct billing in google playstore.

i can add payment method direct billing. but when i try to pay, it failed. when i check google record, got 3 entry but all declined. then i tried using friend phone with digi. managed to do it. what i noticed is, when using celcom, it didn't save and register my phone number. but my fren phone show her digi number in google playstore.

my phone : xiami rn4x - aex rom - celcom
fren phone : xiaomi rn3 - miui - digi

anyone facing the same problem? is it caused by custom rom? or celcom got problem.