How can I fix my TV?

I have a maganovox tv, it had been working just fine, my 2 year old hit some buttons and now all I get is a screen that says "Here is why this will be your next TV", and than shows you all the features. I can not change the channel, there is no volume and I cannot turn on and off the tv. The only way to turn the tv off is through the cable box. please help?