Receiver for licensed can am two seater 48V

Shorts out

I have replaced two of these new control units and they both have shorted out when power is connected. First one I bought and then when it shorted out then they charged me again at "a discounted rate" they said and this one shorted out as soon as the batteries were connected back up again. I ask for instructions but none were sent. Used the same procedure and put the old unit back in both times, won't remotely turn left, and it has worked fine both times. I contacted them for a third time with no response yet.