Hello @gclark2712
Thank you for reaching out on the community and telling us about your issue. I do apologize for the issue you're having. Generally when you add a payment you should be able to add it to an existing invoice so it doesn't calculate on its own. If you could explain exactly how you put them in so we're able to take a better look.
As it goes for reports I believe you're look for a report that breaks it down by invoice. You may be able to do this by going to the register with the invoices and then in the top right clicking on the gear dropdown. From there go to more reports > register report. I believe this breaks it down by invoice so you're able to take a better look but let me know if that's not the case.
Once you get the chance let us know more and we'll see what we can do next.
Thanks,
Quicken Francisco