Well, you have a few options. If you feel comfortable opening it up yourself (and as long as it isn't still under warranty, as this would void that) you can check to see if there is anything loose or disconnected inside. Just be really careful when opening it up that you don't do any damage in the process. If nothing is dislodged or loose, you may well need to replace the screen, when can be done, you would just have to purchase a new one for your device. There are also many instructional videos online on how to open up a tablet, what parts are what, and how to replace a display.
If you don't feel comfortable doing it yourself, you can try a local tech or repair shop.