Two things: Firstly, if you have already reached your target pension value, you are very much ahead of schedule with your retirement planning – well done! Secondly, even though the contribution period has ended, you can still keep your money invested and growing in the same way (or a different way, if you like) until you decide to retire.
If you ever need any information of help regarding your options for anything “non-standard”, just message us, we’re here to help :-)