You can change your credit card information or payment method using the steps below for the app store or website account associated with your BET+ subscription.

iTunes:
Open the Settings app
Tap your name at the top
Tap Payment & Shipping
Update the information. The update must be made to the primary account if using Family Sharing.
Google Play:

Google Play: 
In the search bar, tap the menu/profile icon.
Scroll down and tap Payment Methods
Update the information

Amazon:
Open the Settings app
Under Personal, tap My Account
Select Amazon Account Settings > Payment Options > 1-Click Payment
Tap Edit Payment Method
Update the information and follow the instructions on the screen to save your changes

Amazon Prime Video:
Open a web browser and sign in to your Amazon account at amazon.com
Choose an Account & List
Select Account, then choose Your Payments
Update the information and follow the instructions on the screen to save your changes

Roku or The Roku Channel :
Open a web browser and sign in to your account at my.roku.com
Underneath Payment Method, choose Update
Update the information and select Save

BET+ website (Smart TV):
Open a web browser and sign in to bet.plus
In the top right corner, under the account name, select Manage Account
Under Subscription, select Manage
Under Payment Method, select Change
Update the information and tap Update