I purchased an iPhone 4, unlocked, from Ebay. Now I am told that my carrier will not accept it (Verizon). I tried reselling back on Ebay, but this phone doesn't have a SIM card slot and so it was returned to me because the buyer said it wasn't as described. There are so many choices of iPhone 4's, that I do not know which description is for the phone I currently have. Can anyone help me with this? I know very little about iPhones. Thanks!