It's got ceramic valves? Quarter-turn levers rather than screw-down knobs?
You can unscrew and fit a new cartridge. Unless you know the make of tap, take out one of the old cartridges first to measure, count the splines etc. Some imports may have a strange fit.
It will be something like
http://www.shop.lunns.net/ceramic-disc-valves-42-c.asp
This is a specialist supplier and you can get more common cartridges much cheaper at a merchant or DIY shed.
For example
http://www.screwfix.com/c/bathrooms...tegory=cat820108&price_from=5.0&sort_by=price
note that the ceramic cartridges are not the same as the ones with washers, which can have replacement cartridges in the same way, though just a new washer is far cheaper.