I have a list of customer name with unique customer ID's. In the pivot table it sums up the totals on customer name (so one customer can have more than one customer id). Now if I change the name of the customer and then refresh the pivot table, the data fully disappears?

e.g:
situation
cust name cust id amount
blabla WVGV 1.000
bla bla ABCD 500
This gives 2 different customers in the pivot table with a customer id, which is off cours correct.

Now I change the data to (because the customer is the same customer):
cust name cust id amount
bla bla WVGV 1.000
bla bla ABCD 500

After the data change I refresh the pivot and would expect the 2 customers have become one with 2 customer ID's, but in stead all of the data is gone?

Does anyone know how to solve this?