WEIZE Beach Cruiser Bike - 26 inch

Brand New. Never Used. Assembled (but might not assembled it right according to the video instructions on Amazon) The seat doesn’t hold when adjusted to a higher level (don’t have the strength and tool to fix it). Though it’s perfect for ppl who’s around 5’1. Should also re-adjust the brake before riding (it was working well at the beginning, but while I was trying to loosen it to make it smoother, I accidentally changed sth. and it’s not working now) I just don’t know how to fix it.