PayPal withdrawing extra under the description of Payin4 despite a full one-time payment being made.

[VivNeedsHelp]

Hello.
I recently made a purchase through Dell paying a sum of ~$400.
However not only did Paypal withdraw the full amount, they withdrew an extra $100 under the description of Payin4. To clarify, I have never used this feature before nor have I authorised it. The transaction to Dell failed and only the $400 was returned. 
Paypal HelpCentre was unable to help me as the Payin4 transaction did not show up in my account summary but only on my bank summary. 
I'd like to know how I can reclaim this $100 as I do not want to risk Paypal withdrawing another sum in accordance to their Payin4. 
Thanks.

[PayPal_Chase]

Hi @VivNeedsHelp,

Thank you for your post, and welcome to our community!

I understand you selected Pay in 4 for this transaction, and received a charge on your bank account for the full amount, and then a partial charge with PayPal. When using Pay in 4, a pre-authorization is conducted, which represent a hold on your card or bank. Within 24 hours, we will then complete the transaction and request the money from your card. This can make it look like you were charged twice, even though we only requested the money once. As soon as we request the money, your bank or card holder should release the original authorization. However, some banks can take 72 hours or more. You can see more information regarding Pay in 4 here.

I hope this helps!

Chase