T-Mobile Fraud Wi-fi free minute feature Internet

Last year I purchase an android 4G LG Optima phone from t-mobile last year. When they sold it to me they told me it was a great phone because I could use it with Wi-fi and I would be able to get on the phone or internet for free. To begin with, I almost never can get connected to the internet, not even upload pictures to facebook. These week I got Verizon fios and I decided to use the Wi-fi signal with my t-mobile. I got a message on the screen that minutes used via Wifi calls will be deducted from my account. I went to the website and there is a page stating that there is no cost for calls made with Wi-fi. Then I immediately call T-mobile, they had the nerve totell me first that you need to add this feature, then they said what kind of phone you have. I told them and they said this type of phone doesn't have or accept this feature, that I could use it for the interinet. Why they did not specify this when they sold me and charge me 124.00 (on sale!) for this phone. That is misleading the customer. I did more research on the internet about minutes charged when using Wifi and the search lead me toT mobile support page where a bunch of people have the same problem, and getting nothing but bogus answers from customer service. There is no such a feature, it is a fraud, and T-mobile can care less. Hope some one sue them for taking advantage of consumers. It is funny how they could not give you information or a log on the calls you make, not even at the store. You ask and they reply they do not have this information why??????They are a ripoff