How can I get a widescreen picture on my widescreen Beko TV?

I've just acquired a 2nd hand Beko TV (Model no. NR 28C748WN3 ) without a remote. We accepted it as we didn't have a widescreen TV and were fed up of missing sub-titles, people dropping off the edge of pictures etc. But now although we have a WS TV we're not getting a widescreen picture - there's a gap of a few inches to either side and when watching a film or DVD we get a couple of inches border top and bottom. Can't seem to find any knobs or hidden panels on the TV itself. We are able to change channel via our Virgin box remote but can't change any other settings. We have a Total Control universal remote but I haven't got the foggiest how to programme it or what to programme it with in the hope I might be able to access some screen size settings. Can anyone out there help?