My flushing system has broken, can I replace it?
The first thing to identify is whether you have a dual flush or standard cistern. Dual flush cisterns are easy to replace and a replacement kit will be available in most cases. For traditional cisterns, many manufacturers now produce cistern content kits which make inter-changing your old cistern relatively straight-forward.
If you need advice you could take a picture of your broken fitting and bring it in to your local Chadwicks or Plumb Centre branch where they will be happy to discuss your requirements.