I just bought a phone from ebay but its got some faults, wot can i do?????

It an iphone first gen i won the bid at �97.......all the description said was iphone complete with docking station. when i got it, the usb lead has a split in one end, so the bit u plug into the computer looks like its hanging off but still works i think. also, along the top of the screen it looks like the colour of the screen has run (like its been dropped in water)........EG when i have a complete black screen up, the along the top the colour isnt black its more greyish, and theres a little spot further down the screen which has the same thing. another thing is that the speaker sounds funny. on my brothers same phone ringtones are perfect, but mine sounds crookey and like theres water in the speaker, and the message tones sound the same, and like the phone is struggling to play ringtones and message tones.