Improve Invoice Itemization

I was wondering is there a way to make invoices itemized more cohesive as so to not confuse the customers. In this example it’s regarding an applied discount and the customer was asking why when they signed up they only Paid $30, but all invoices thereafter have been $50. The reason is because they got a $20 discount applied at signup, however in the purchase invoice it’s itemized confusingly. It starts by showing the $30 discounted price at the top instead for the regular rate of $50. I will give you examples of the Original invoice and a Mock-Up invoice I made that shows how it could be itemized better for us and customers:

The Original Invoice:

The Mock-Up Invoice I made/photoshopped: