When you make a purchase though Paypal you are not covered by section 75 of the Consumer Credit Act and therefore you cannot claim your money back from your credit card provider. However, Paypal transactions are covered by the Visa Debit Chargeback scheme.
When you make a Paypal purchase the corresponding amount is taken from your primary payment card or current account associated with the Paypal account. This makes it straightforward to determine whether a Visa Debit Card was used for a particular transaction or not. It can be more difficult to make this link it you already had money in your Paypal account. This might be the case if you sell items on Ebay, take payments by Paypal and don’t regularly withdraw your money. However, it is still worth putting in a claim, especially if you have missed the deadline for using the Paypal dispute process or were not happy with the outcome. It is important to remember that you have 120 days to make a claim to the bank that issued the card.
You also have the benefit of Paypal Buyer Protection, but this offers only limited protection for consumers.