Filed a claim for not receiving tax refund

IRS sent my tax return July 08, 2019 & to contact them on August 5th if i don't receive it in the mail (which i didn't) and i filed a claim & they said to contact them September 20th if i don't receive anything then.. I gave my new address to the IRS IN PERSON & updated my new address with the postal system. How will i know this 2nd check is being sent to the right address? I've tried to contact the IRS to speak to an actual agent with no luck.