I, too, had only 4 contacts... I went on ebay and found the terminals.. they were $6. took only a week from China.
I just changed it .. 4 screws on the back. popped out the current damaged contacts.. put the new one in.. replaced the 4 screws.. plugged it in and it worked.. it is charging now.. took 20 minutes.. Just need to have a screwdriver small enough.. I had bought a small kit in Micro center..