When I press the reverse direction button, fan actually speeds up in same direction and then goes back to original speed. I complained on their website and they quickly sent a new receiver, but it still does the same thing. Fresh batteries in the remote control didn't help. The fan has no pullchains. Is there anything else I can try, maybe with the remote control? Thank you!

Since you replaced the receiver, the only other part is the remote. Try replacing the remote.