@cad3nas - it doesn't work like that. Understand that the whole reason to submit a tax return is to settle up the taxes owed to the IRS, as calculated on the tax return, compared to what employers withheld on paychecks.
That difference creates the refund or taxes due
your tax return will be calculated as if you were married the entire year as it is the status on 12/31/20 that matters.
the way you get back 'all that money' is simply completing your 2020 tax return. Whatever the refund is reflected the net of the taxes you owe less what was withheld.
