Payments showing as negatives

I am embarrassed to ask for help on this topic but here it goes. New user and new at sending invoices for services. I have been using the discount field to show amount owed. For example someone owes $100 so I put that on the discount field. They make a payment and it shows as negative.
I found out I was doing it wrong after a client pointed out that the amount owing was negative hence whey they didn’t pay for the invoice.
I went searching around and found out I should have added an item under products instead of using the discount field.
Anyway I started doing it the correct way now.
Is there a way to turn over 100 invoices that have been paid from a negative amount in my dashboard to a positive amount?
I hope this all makes sense.


If it isn’t too many you may want to delete and then recreate the invoices.

Thanks Hillel, unfortunately its approximately 100 invoices