A buyer asked me a cancel order and refund to other paypal account

[defonil8]

Buyer name: jamisa_27 had bought an item from my listing he did pay through PayPal and It was late to deliver by my end.

Yes, I have some troubles and It got late.

He got mad and give me Negative Feedback with offensive words. Also, he told that he wants his money back or he will close my eBay account. So I did cancel the order and gave him a full refund. 

after that, he told me that his old account is not working anymore he wants to refund to his new PayPal account.

I already refund him. So What Do I need to do? Can you please help me to resolve this.

If you can please consider about the remove Negative feedback

every detail in his messages

Item #: 282864759165

Date Sold: 01/14/2019

Buyer:  jamisa_27