Two data sets with the same fields in and the data is compounding in a graph and a table. - Power bi

Hi

I am getting to grips with powerbi, I've done a 7 hour course and clearly have some way to go, so any assistance or pointing to the right direction would be very welcomed. I'm comfortable with Excel.

I have connected to three SQL data views:

1.) Sales - with fields date, amount for each sale client id, year, accounting period (base data)

2.) Fees balance - with fields, client balance, client id, year, accounting period

3.) Client data - with fields, client id, client name, account manager plus other client related fields

In the relationships I have connected them together via the client identifier one client in each case where the one is the client.

Next set up a table with Year & Period from sales, Client Id from client data, fees balance from fees balance.

The result is the balances per period per client are massively over stated. 

Help and thank you.

Best wishes

Ros