The HR is asking an employee to work after his resignation. What to do?

Dear sir/madam,

I am working as a sales staff for footwear leather products in Dubai for more than 3 years. I submitted my resignation letter last July 31, 2022, and my last day will be on August 31, 2022.

I did not put my reason in my resignation letter but when asked, I said that it is personal and I need to go to my home country, however, our HR/accountant wants to extend it until September 20, 2022.

His reasons were there will be no staff because some staff will be on vacation. I need to arrange my final settlement. He also said that I’m selfish because I don’t want to support the company.

Kindly please help me.

Thank you!