What you actually get
Catch-up plays a programme that already aired. It is not a recording you keep forever. Moon Start includes 7 days, Moon Plus 14 days, and Moon Max 30 days, on channels that allow replay.
A channel without catch-up still plays live. The guide marks replay where it exists. If a match has no replay the next morning, that channel did not offer it. Changing plan does not add replay to a channel that never had it.
Where to find it
Open the channel and look for the replay or the programme list in the player named in your email. The exact menu differs by player. The days you can go back do not. Plans are compared on packages.