BB Bold :: 9790 Speaker Not Working?

I am Italian and I bought a new blackberry 9790 about four mounths ago. The telephone has a problem, sometimes speaker doesn't work and I can't listen the call, if I switch to the hands-free speaker it works, but in normal use with speaker it doesn't work, After any days the phone works fine, with random frequency. I updated the software with the last 7.1 os version but the problem remains. I read in many forums that many users has the same problem, so it is not possible to buy a phone for 499 euro and to have this kind of problem! I can't find any RIM telephone number here in Italy to have a support for this problem. The telephone has about four months, it is new, and it is in perfect condition,