English to Italian Bus/Financial Investment / Securities derivati

How can I complain?
In the first instance we recommend you speak to your broker in relation to any complaints.
Complaints to the XXX must be made in writing and, in the event that it is made by a company, must be signed by a director or equivalent officer.
Complaints should be sent to XXX [indirizzo e dati della Borsa in questione].
The complaint should include sufficient information to allow the XXX to properly identify the trade(s) or activity complained of and establish the ** basis for any alleged loss **.