There is not much you can do since the IRS is the only authority that can Approve and Issue a tax refund. If your address was incorrect or has changed since the federal tax return was filed, then go to this IRS website for change of address information - https://www.irs.gov/faqs/irs-procedures/address-changes
Since you are located outside the US you can call the IRS International desk if you are unable to call the IRS using the US toll free number of 1-800-829-1040.
The International Call Center is operational Monday through Friday, from 6:00 a.m. to 11:00 p.m. (Eastern Time):
Tel: 267-941-1000 (not toll-free)
Fax: 267-466-1055 (for international tax account issues only)
You can also contact an International Taxpayer Advocate.
Go to this IRS website for contact information - https://www.irs.gov/advocate/local-taxpayer-advocate#PuertoRico