phone wont turn off. screen maginfied

second time i have written this becasue this site is crashing my computer! really fed up with apple right now.

so i have my second iphone 3gs. i cant use it because the screen is maginfied. like you are looking though it through a magnifying glass. not like its in large type font. the texts and screen are all cut off. i cant turn it off because the "slide off" is at the top of the phone and the screen is only giving me the lower part. i cant get into my phone because i have it on password protection and i am only given 4 numbers since the screen is magnified. really irrated right now. only thing i can think of is that its the SIM or an app i have. only common link between old and new phone. old phone had a sensor issue and crashing. any advice? not sure if i should try apple first or att. apple said it was the SIM last time, so i got a new one. and then att said it was the phone.