Suggestion needed for Template (Budget Vs Actual)

Hi, our company always have those Upgrading project. They have set aside a certain amount for each project. Example, $3000 for Chairs. Whenever we received invoices pertaining to this budgeted $3000. We have to put it in excel so that we know how much is left in this $3000. However, most of the time, a single $3000 budget is make up of many invoices. This make presentation very ugly and We need constantly update formula and inserting row etc. See attached file and you know what i roughly mean.

Does anyone have any better idea how to keep track?