Hi there, @Agape D. I understand how being unable to turn off the automatically apply credits feature affects your transactions. Allow me to share some information and walk you through some steps to resolve this issue.

Yes, there's no option to disable vendor credits in QuickBooks Online. We can only turn off the Automatically apply credits feature for customer invoices. 

In the meantime, let's isolate this issue and access the transactions via incognito or private window. This allows us to determine whether the problem is due to browser caching. Too much data stored in the browser affects your account's performance. To proceed, refer to these keyboard shortcuts:

• Ctrl + Shift + N for Google Chrome browser
• Ctrl + Shift + P for Mozilla Firefox & Microsoft Edge browsers
• Command + Shift + N for Safari browser

After that, open the bill payments again and see if the vendor credits automatically apply. If this works, I recommend clearing the cache in your default browser to refresh the system. Using other supported browsers also aids in narrowing down the problem.

In case you'll want to delete the vendor credits, follow the steps below:

1. Go to the Expense menu, then select the Vendors tab.
2. Locate the name of the vendor.
3. Under the Transaction List, mark the check box beside credit and click Delete under the View/Edit. 
   
4. Press Yes to confirm.

To learn different ways to record a refund or credit from a vendor, refer to this article: Enter vendor credits and refunds in QuickBooks Online.

I'm adding a few resources below to help you with managing vendors and their transactions and discover helpful tutorials:

• Expenses and vendors
• Watch step-by-step videos to learn your way around QuickBooks

These steps should verify if the strange behavior is a browser issue. I'd like to know how you get on, as I want to ensure we resolve this for you. Kindly update this thread if you have additional questions about this vendor topic or other program concerns. Have a nice day!