The acetate material which makes up the frame of hand-made sunglasses is an organic material that can sometimes ”move/bend” when exposed to temperature differences during freight for example. This can result in the temples/arms of the sunglasses not being 100% level. Our temples are designed and crafted to be adjustable to ensure the perfect fit and the problem you describe is easily adjusted by very gently bending the temple in the hinge. If you are not comfortable adjusting the temples yourself I would recommend visiting a local optician.
To fix the temples and make the frame straight you have to gently bend one of the temples.
You can choose to bend each of the arms in opposite direction (one up and one down) or only bend one of them in one direction. In order to bend you take a gentle but firm grip in the front of the frame with one hand and in the temple with your other hand (Close to the hinge). Then gently bend a tiny bit and check the frame.
To check if the frames are even place them upside down on a flat surface and check if both temples touches the surface when lying flat. If not, you just bend slightly more until you are satisfied.