Refund 2020 taxes not received yet?

Dear TT,

I got an extension on my personal taxes and paid a large sum earlier in the year by April 15, 2021, for my 2020 taxes. But when I filed in Oct 2021, it runed out I owed a lot less (one third less) but have not received the difference back and could really use it. If I owe this year, do I just pay the difference?

 

Thanks,
Greg