@joyanyu , while generally with the above suggestions --- I would suggest taking care of the problem at source:
IRS section 1445 requirement for FIRPTA withholding is based on "foreign person". Here is a link to the IRC defining Foreign Person: https://www.irs.gov/individuals/international-taxpayers/foreign-persons.
IRC section 1445 applicable to disposition of US RealEstate Interests is describe the need to withhold FIRPTA tax from the transferror ( one whom disposes ) and if not the Tranferee ( the receiver/buyer of the asset ) is liable . Thus the title company is trying to avoid exposure . But they are wrong if , and only if , both you and your spouse ( I am assuming here that you are selling your home and that you are each a resident-- Green Card or Resident for tax purposes , having met the substantial presnce test, filing form 1040 return for the year in question) are both US PERSONS ( for tax purposes ). Here is a link to IRC 1445 -- it is long and tortuous but covers all kinds of situations -->
https://www.law.cornell.edu/cfr/text/26/1.1445-1
Here is another page from the IRS explaining FIRPTA and covering the area and has FAQ:
https://www.irs.gov/individuals/international-taxpayers/firpta-withholding
BTW , I don't see how you can use form 843 for seeking an early refund of the FIRPTA withholding -- @DaveF1006 's link covers the use of the form but ( unless I missed it ) does not include the use for section 1445 early refund.
I would hope that you can convince the Title company or their lawyer that (a) you are not a "foreign Person " for purposes of IRC 1445 and (b) that you are a resident for tax purposes and hence the FIRPTA does not apply to you or your spouse.
BTW -- what is your visa status -- Green Card , H-1B or what ? How about your Spouse ? What is the real-property you are selling --- your own residence or income property or what ? Is the total prpoceeds more that US$300,000 ?
Is there more (I can do for you ?
pk
