Issue with summing values in spreadsheet with Pivot Table

I have this simple scenario:

Supplier	Inv Num	Transaction Amount	Tax Amount
Supplier Test 1	ZAADEa1	-67	-13.4
Supplier Test 1	BBFE443	-341.6	-68.32
Supplier Test 1	BBFE443	341.6	68.32
Another Supplier	AADD_56	-9.96	-1.99
Whatever Supplier	TEST45	-22.05	-4.41

I'd like to be able to sum the Transaction Amount and Tax Amount on each distinct supplier and invoice number, so I would in the above example I would end up with:

Supplier	Inv Num	Transaction Amount	Tax Amount
Supplier Test 1	ZAADEa1	-67	-13.4
Supplier Test 1	BBFE443	0	0
Another Supplier	AADD_56	-9.96	-1.99
Whatever Supplier	TEST45	-22.05	-4.41

In this example, there were 2 lines for Invoice ZAADEa1, but after summing there is just one line:

I tried a Pivot Table, with "Supplier" as a Row, and Tax Amount and Invoice Amount as Values, and that looks nice and tidy, like this:

1Untitled.png

However, without the invoice number next to the supplier, it's no good. If I include the Invoice number, then due to the way Pivot Tables work, the nice tabular format is lost and it looks like this:

2Untitled.png

Is there any way I can achieve what I need using a Pivot Table?

Any advice much appreciated.

Thanks