Help! My boss wants me to return to work while I'm on vacation

Dubai - An employee is not required to return to your work during the period of approved vacation.

I am working in a bank based in Dubai since March 2016. Currently, I am on vacation in my home country Pakistan. My employer called to tell me to cut short my vacation and rejoin duty due to increased workload. Since I have some family commitments in my home country, I am unable to go back to work before my vacation ends on September 9, 2018. Can I refuse my boss? If I want to quit, what is the legal way to do so from Pakistan?
Pursuant to your queries, you are not required to return to your work during the period of approved vacation. It is up to you whether you wish to rejoin duty before completion of your sanctioned holiday, at the request of your employer, or after your vacation ends.
Upon your resignation, you should serve the notice period and work until the last day of notice period for you to be eligible for full pay and all end of service benefits, unless your employer waives off the notice period. This is in accordance with Article 118 of the Federal Law No. 8 of 1980 regulating employment relations in the UAE (the 'Employment Law') which states: "A contract shall continue to be valid throughout the period of notice referred to in the preceding article (Article 117 of the Employment Law) and shall terminate on the expiry of the notice period. The employee shall be entitled in respect of the period of notice to full pay calculated on the basis of his remuneration and he shall be required to perform his works during that period if the employer so requests.
The parties may not agree to dispense with the requirement as to notice or to reduce the period of notice, but may agree to increase it."
Based on the aforementioned law, upon your resignation, your employer may ask you to work during the notice period. Annual leave and notice period should not be merged together as the employee must work until the last day of notice period.

Know the law
An employee is not required to return to your work during the period of approved vacation. It is up to the employee whether he/she wishes to rejoin duty before completion of the sanctioned holiday, at the request of the employer, or after his/her vacation ends