Why cannot I not change channels with the Channel up and down button?

I purchased an ONN 19" LCDV Model LX19T3W Stock #ONN19LCDV

On the remote control there is a button up and down for volume and also for channel change. The volume button works fine, but I cannot change the channels. The only way I have been able to change a channel is by putting in the number and with so many stations available now, that is a pain in the butt. When I use the Channel Change button it always goes back to Channel 2.

Is there not some way to rectify this problem?