efile Federal Taxes but then send in paper 1099X; what happens?

I efiled through turbotax my US federal taxes, which I owed money, say about $100. But then I got a modified late 1099-DIV, lowering my tax burden slightly, so I only owed the IRS $50. I refiled with a paper 1099X about two weeks ago but got debited the $100 today.

When the IRS processes my 1099X will they send me back the extra dollars that I overpaid?

I’m assuming you mean 1040X for an amended income tax return.

I believe the IRS still says 8-12 weeks for processing these. It can be much longer, in my experience. Your check for any refund will take about three weeks after they’ve processed the amended return.

You actually have a full 3 years to amend a tax return, so assuming you used the correct form (1040X) you should be fine.