I had a payment arrangement set up which said it would keep service on through 9/30 but today my services are off.

Hi there @user_8iecwb, thanks for taking the time to reach out. Are you sure you set up a payment arrangement and not a scheduled payment? A scheduled payment is just a payment set for a specific date but doesn't protect your services, a payment arrangement gives you extra time to pay your past due balance and prevents service interruption. 

1. Sign in to the Xfinity app.
2. Tap the Account tab.
3. Under "Bill details," tap Bill settings.
4. Look for payment plan or arrangement information.

Set up a payment arrangement for your past-due balance