Ordered an electric 'motorcycle', err... scooter

[ClodMaxx]

got an update on saturday. they told me to pay shipping and tax applicable for my state: $350 and $75 respectively. then they issued a refund the next day of $75, and the note said 'you sent too much money. we are returning the rest. thank you.'

i'm curious as to how over-engineered the system is. can i use a 52v battery pack instead of the 48v it comes with to get a little extra speed?