No, no, no...
But if you feel you must, all I can say is you'd have to buy the bag and cut up the canvass. Go for a fake, since this isn't a real LV item anyway and there's no worry about authenticity.
You'd have to have the capability to sew up leather (or know somebody who does). Buy a leather case for your model of phone and take the stitching out so you have a template for the shape of the leather you're cutting out of the LV bag. Then reconstruct the LV leather to form the shape of the case.
An awful lot of work!