I purchased a Macbook A1342 2010 (white one) from eBay and it arrived with software and a password on it. This was not in the seller's description. I instinctively (have had many macs before) used Disc Utility to wipe the disk and reinstall OS. All was going well until when I went to sign in before installation began it said: "This item is temporarily unavailable". I went on the internet in search of answers and someone suggested to use Online Recovery (which I did) and it reverted back to OSx Lion. The exact same error happened with Lion as it did with El Capitan right before it begins installing - "This item is temporarily unavailable". The Apple ID that I used has been used with Macs before but no older than El Capitan. I tried two Apple IDs which have both been used on Macs and both were refused. The seller is saying it is my fault despite him being the one that sold a locked product without stating so and eBay have ruled in his favour. How can I go about fixing this mess?