LOL, I don't think I've seen a vertical hold adjustment on a TV set for about 25years at least!!
anyhow, it's not vertical hold, it's the aspect ratio.
does it look the same on all channels? or if you have sky does it look the same on sky channels and normal terrestrial TV?
Problem is it may be a setting on the TV that is wrong, or if you have sky or freeview then it maybe a setting on the sky or freeview box thats wrong.
look for a button on the remote labelled something like 16:9/4:3 or maybe letterbox
If you can't find any thing either look in the manual for how to change the aspect ratio or post the make and model and somebody will probably be able to help