Elkay Crosstown Stainless Steel 31-1/2" x 18-1/2" x 9", Single Bowl Undermount Sink Kit

Installed upon recommendation from our kitchen contractor. The pitch to the drain is not sloped well and food just travels around the sink and not easily to the drain. The stopper does not allow food to drop to the disposal and we are always pushing our food bits down with our hand. And worst, it's now staining and blotching after less than four months of usage. The cleaning directions suggest vinegar and baking soda and it's only partially effective. The instructions suggest drying your sink when done. Who does that? We expected better and unfortunately our contractor won't check out our concerns.