Alitalia / payment not received

I Cancel the ticket OUMOUU on August 1st.
I was told to wait 10 business days that Alitalia would contact my credit card company to proceed the cancellation.
So far Mastercard haven't received anything from Alitalia. The email I send to alitalia.brasile I don't even get an automatic response and Stefany from Customer service Brazil told me they never reply, that I need to wait.
No one on Alitalia's side gives me a clear picture of my request! I've tried email, facebook, telephone...It's very frustrating!