Definitely still getting PBS,That's TV and Talking pictures on my Freesat integrated TV. As above suggested if it's not a Freesat receiver a rescan might do the trick but a genuine Freesat receiver with the Freesat electronic programme guide will find channels that change frequency automatically. If you still can't get those channels then you could need to replace the LNB on your dish as they do quite often develop faults where they become effectively deaf to certain frequencies. They can be bought very cheaply these days. Hope you get it sorted.