Calculate value of sales per product per customer

I have a spreadsheet of sales over a week, with various product categories (hammer, pliers, tape measure, saw etc.)

I need to calculate how much each customer purchases of each product over that week.

I've used SUMIF but that only adds up the total for each customer and doesn't break it down to individual line items.

I'm sure there is an easy formula to include so any suggestions would be appreciated.