I wish to stop a direct debit receipt. Please cancel.

[sandypebbles]

Other members cannot cancel the money/fees you owe

If you want to cancel something you signed up to, agreeing to pay the fees for doing so, only you can do that

[paper-jack]

If you mean you want to cancel Ebay plus, Ebay's help (button top of the page) states:

Changing or cancelling your eBay Plus membership

You can check the details of your eBay Plus membership at any time, including whether you have a monthly or annual membership, your next payment date and your payment method.

View eBay Plus membership - opens in new window or tab

Change or update your payment method

To update your payment method for eBay Plus membership fees:

1. Go to your eBay Plus membership page - opens in new window or tab.
2. Select Edit membership.
3. Select Change payment method.

[kdapra58]

I wish to cancel a direct debit 

[davewil1964]

Refer above

[sandypebbles]

Then do so. You do not need to tell other member or ask or permission