DramaBox Backup Payment Issue

I am a Dramabox user with a one-week subscription that I purchased on 6 July via Google. Since activating this subscription, I have been experiencing a persistent problem with the backup payment feature in the app. Whenever I try to select or change any type of backup payment method, the system shows an error message and does not allow me to proceed. Because of this, it is effectively impossible to set up a backup payment option after having an active subscription, which puts customers at a disadvantage while the company continues to benefit from our payments. I have not yet been able to resolve this issue and I have not contacted customer service before this complaint. I request that Dramabox urgently fix this backup payment error on my account and ensure that I can successfully add and use a backup payment method without any further problems. I also ask for this issue to be checked on a broader level so that other users do not experience the same situation.