I just bought the BB, so no, I still don`t have a data plan. However I spoke with the carrier and they mentioned I do not need a data plan to access the internet via wi-fi or to access the applications via wi-fi.
They also said this model is still not available in my country and that I need to call Blackberry and ask for the internet configuration info. Which is very weird. Specially weird, since the BB was working just fine on the first couple of days.
I do appreciate all your help aiharkness and I will try your suggestions. I`m also going to my carrier`s store to see if anyone may help me there...