I'd send it back. You paid good money for that copter don't settle for anything less. That noise will drive you crazy over time, you can wait 2 weeks for something you will use for years, and you will probably have to send back anyway.
Thanks Andy. It's not really a hop it's that the motors start to shut off and then surge up for just a second and then shut off. This all happens after the bird is on the ground. It's really not noticeable unless it's windy.
I have the same issue the motors pulse (rev up) slightly before cut off. It really makes it difficult to land without the bird wanting to flip over. It's only a problem on windy days.