I keep receiving an invoice from Dell Marketing LP dell_28@dell.com for $50?

Hello on May 10, I started getting requests on my paypal account for $50.00 for an order for a refurbed monitor. . The Invoice even says balance of zero. Is this a scam? I used a $50.00 Dell Giftcard to pay part of the order and the rest was on a credit card.

I thought it was a scam and ignored but after looking at the Invoice pdf it says balance of $0.00 on the invoice form and it has the correct order number on the invoice PDF.  What is going on and why am I getting these invoice payment requests via paypal, which I have never used to pay before on any Dell.com purchase.  Is this a scam?

Thanks