PayPal transactions are reversible that's why the escrow you contacted rejected your request. However, you can buy bitcoin with PayPal through  different websites. I've used virwox before and it's already a long time since I've used them.

But upon looking at their dashboard, they are still offering it. And when you are done buying bitcoin there, you can now ask the escrow to do the deal for you since you have bitcoin already.

edit:
Thanks for the correction, it's typo.