SMS problems

[nat1]

hi,

I just my samsung intrepid about 2 weeks ago (my first one anyway) and I have had problems of it randomly quit sending SMS messages. so i took it back and exchanged it for another one but it had the same problem. I am approaching the end of my 30 day trial period and would really REALLY like to keep this phone but if this continues I cant. so does anyone have any advice? service at my home is not great but once it wont send a message it wont send another one till I pull the battery (not just a soft reset), no matter the service. i can still revive SMS, make calls and get emails. Im stumped and frustrated at this one...