If you've made a payment to PayPal through your account but you're not immediately seeing this in your PayPal purchase history, it's most likely that this was set up as an eCheque.
An eCheck is an electronic funds transfer from your bank account to another customer's PayPal account. It's used to fund a payment that is sent from your PayPal account. It's like writing a check, but you send it electronically.
You should be able to cancel this via PayPal.
Here’s a snippet from PayPal's website that might help you too: 'To cancel an eCheque, you need to contact the recipient who'll be able to cancel the payment from within their PayPal account. If the eCheque gets canceled, the money will still leave your bank account, but it will be credited to your PayPal balance within 4 - 5 working days.'
I've also linked their message center if you wanted to contact them directly about this.