Samsung Phone

my pictures are not being saved to my gallery and the past week I cant get 3g to come up on my phone and when calls come in Im not getting the contacts who are calling in and i did before. It gets very hot when im on it for 10 minutes I think there is a problelm with it and it has gotten worse since i got it around Jan 3. I would like the warranty on it and have it replaced since there has been so much trouble. I have taken the battery out of it and have turned it off and on and still not what i had when i first got the phone. I bought 3 phones around the same time but I do not have my receipt was in the middle of moving at the time.