Simple invoice status monitoring dashboard based on pivot table

Hello,
I would like to create simple invoice status monitoring dashboard. My current idea is to create it based on the pivot table + pivot chart.
The following description is a kind of simplification to make my needs easy to understand.
Each month I will extract from my accounting system three kind of information:

• invoice number
• invoice issue date
• current invoice value (this value changes depends on the payments received from the client)

These information is represented as columns A,B,C in Sheet1 in attached file.
Information in Column D is manually added by me and represents the month at the end of which there is the invoice value from the "Current invoice value" column.

In Sheet2, I have created simple pivot table and pivot chart, where I would like to monitor overall invoices status (based on the pivot chart visualisation) and status per invoice (based on the pivot table).

My two preliminary questions are:

• How to change pivot chart construction so that on the X axis I will have month (without doing any changes in the pivot table).
• How to modify the data series in pivot chart, so I will not have a columns splitted by invoices (just want to see overall value of the all invoices summarized, not per invoice).
• Do you have any idea how to create an additional chart and pivot table that will show the status of all invoices (i.e. their current value), but without taking into account newly issued invoices? For example, I have data at the end of September which, apart from containing data on the value of invoices issued in previous months, also have the values of newly issued invoices, which distorts the information on the values of older invoices. Such a chart and pivot table would inform whether contractors are paying for older invoices.

Thank you very much!