After you file

It is not true that you did not "have to declare" your unemployment.   The tax law changed in March and now the first $10,200 of unemployment is not taxed on your federal return.  But anyone who received unemployment has to enter it on their tax return.  So entering your 1099G was the correct thing to do.  The IRS is issuing refunds to certain taxpayers who paid tax on unemployment.

So far the IRS has issued over 8 million of those “extra” refunds for tax on unemployment.   The IRS has not announced when the next batch will be sent out, but they are still working on them.

The IRS is recalculating refunds for people whose AGI is $150K or below and who filed before the tax law that changed the amount of unemployment that is taxable on a federal return became effective.   

The IRS began to send out the additional refund checks for tax withheld from unemployment in May.  The refunds are being sent out in batches—starting with the simplest returns first.   If you are eligible for the extra refund for federal tax that was withheld from your unemployment the IRS will be sending you an additional refund sometime during the next several months.  TurboTax cannot track or predict when it will be sent.  The IRS has not provided a way for you to track it, so all you can do is wait for the refund to arrive.

https://ttlc.intuit.com/community/tax-topics/help/how-do-i-get-the-new-unemployment-benefits-if-i-ve...

Please read this news from the IRS:

https://www.irs.gov/newsroom/irs-continues-unemployment-compensation-adjustments-prepares-another-1-...

https://www.cnet.com/personal-finance/taxes/more-unemployment-tax-refunds-are-arriving-but-when-here...

And.....you say that you mailed your return.  Mailed returns are taking a VERY long time to be processed.   So it might be that that IRS is still working on your return.   Did you use a mailing service to track it when you mailed it?   Has the IRS cashed your check?