I thought that the default (clean) install of Vix should have OpenTV EPG enabled. Maybe not?
In any case, if you are just using 28.2, there is no need to install and run EPGRefresh as there is a built-in OpenTV EPG downloader available in Menu/Setup/EPG. This will start an EPG download automatically five minutes after boot and at a configurable interval afterwards. You do need OpenTV enabled in Menu/Setup/EPG/Settings, though!
If you are a keen radio listener on 28.2, you will need to enable the Freesat EPG if you want to see the full week's schedule as the OpenTV EPG reader doesn't seem to have the radio schedules. Be aware that having both Freesat and OpenTV EPG settings enabled can lead to some oddities with programme details or conflicts when a programme's details or schedule time are changed. Enable both EPG readers only if you must see the radio schedules.