iPhone 3GS 16gb, needs repair *

iPhone 3GS in a very good condition for sale. The phone was working fine till I changed the back cover. Since that it has difficulty in reading the sim card and sometimes it reads it and sometimes not. You might be able to fix it or use it as spare or repair. I can provide you with the serial no to prove that the phone has not have any issue or what so ever. Any question feel free to ask. Cash on collection only.