How do I change my address? The house number is missing

Dear support team
 

I found that my address is missing house number and I called 0800-0402, but it seems it’s Automatic Voice Recognition and I can’t reach to the staff. 
My Klantnummer is 9********* and I need to add A as addittional house number.
And also I tried to change Klantnummer 4*********’s billing address but it’s not updated.
Please advise me how to update, or which number I should call.

Klantnummer 4********* is the correct aaddress, just FYI.

Kind regards, Kenya
 

Admin: removed klantnummers for privacy