Samsung SGH-P777

after i made a phonecall to my friend, (this is after three days i got my phone) my screen went distorted. it basically froze, i turned off my phone... turned it back on and i got t.v static on my phone. i can still make and recieve phonecalls but i don't know who's calling me.. and i never know if my calls are getting through. before that i've had an issue too where half of my buttons wouldn't work, especially my talk key.
this is a fabulous phone, but i'm just wondering if any of you have the same problems as well. (returning it and they better give me a new one, i have warranty)