Hey there @Sandebro!
What a great question! I will be more than happy to help!
Currently, the only way to use your Plenti points to pay a bill is to go an AT&T Company Store. I apologize for any inconvenience this may cause. Our store locator tool can help find the nearest location to you! You will to bring either your Plenti card or know the PIN to your account in order to use it.
I hope this information helps! Have a fantastic day!
Katie, AT&T Community Specialist