Transeo Land Cruiser bicycle

Every thing works good just not the rear brake for some reason the brake cable keeps popping out of the metal brake adjuster every time you press it which causes it to rub against the disc you just need to push the cable back in the adjuster and it will be fine and the wheels just need a little bit more air. The bike has front breaks it’s just the rear ones that mess up. Bike has front suspension! Pick up in orillia