controller not syncing to console

I brought a new Xbox controller from eBay, admittedly I know it was a cheapy but I've sorted the problem with the seller. I didn't get a replacement, just a full refund, so I would like this controller to work.

It flashes when I try to sync it but it just keeps on flashing. It continues flashing for about 2 minutes before it stops. I know it's not the console because the other two controllers we have sync up perfectly fine and there are no problems with that.

Please help?