I have a question about my cell phone?

i have a att samsung captivate and i bought the best buy protectionplan bec it seemed to offer more then att now att offers same and they dont bull **** around with gettin you your new product , i turned my phone into bestbuy 4 months ago bec it kept freazing and locking up all they did was send it for repair and they had for a month ,then i got it bac still freazes and now speaker works off and on cuts out , i have no 3g or any signal , i have to restart my phone 15 times a day no joke just to get my calls and text , then on top of that my msging crashes all day long . if i take it back into best buy will they just send it out for damn repair again or will they just finaly decide to give me a new one in mail , ,i think my phone messes up bec it was first batch of phones made i got it first day was released and everyone else ik dosent have a problem with there captivate , some ine pls help idk what to do