Try a factory reset on your TV, this will go through the correct returning process and will aid in restoring your channels. You can usually reset the TV in the settings.
Your info is a little confusing.
Your profile indicates you are receiving Freeview via Satellite on a Dish antenna.
Your TV has Sat and UHF tuners.
Yet you say you have checked the aerial (which I guess is UHF) and cant tune Digital Channels?
What sort of antenna are you using, which socket on the TV is it plugged in to, and are you tuning UHF or Satellite?
It's difficult to diagnose any problems when the info supplied is very limited and to me seems ambiguous.
If you have done a factory reset on a sat tv may have changed the dish settings
Go into the set up menu for satellite and look for either dish or lnb settings
if you find numbers likw universal,10600,10750,11300 change to either 11300 or 10750 as most common
Sorry Melissa but the intent was not to be obnoxious but to elucidate the info needed to help you. So many people ask for help here without supplying enough basic info. In order to help we need to know quite a bit of background info. e.g. Sat or UHF, Type of antenna, Location, Brand and model of TV or Box, how it's all connected together and what the problem is. We don't have a crystal ball. Posting pictures of setup and connection is also extremely helpful. Now that we have your info we can help. As Willis said. If you have done a factory reset and are tuning the Sat Tuner then all your settings will have been returned to default and most likely your LNB freq need to be changed. Std freq for LNB are 1075 and 11300. If your setup shows 10750 then change it to 11300, or vice versa. Hopefully that will solve the problem. If not then a picture of your setup screen or list of paramaters set could help.