Triton Topaz T100si

I purchased a Triton Topaz T100si shower as a replacement for my old shower, at first it seamed ok, the temperature regulation on the shower is brilliant, but I am not impressed by the flow rate. The old much cheaper shower at cooler temperatures had a better flow & was much more powerful. The quoted flow rate of 8 litres per minute is much more than the shower can achieve. Now with the shower being less than 4 months old I have a problem with the pressure relief device. I contacted Triton only to be told I would have to purchase a new one for £9.70 + £3.50 postage, what a joke! Customer service is very low on their list of priorities, you could get more satisfaction from a chocolate fireguard! For £250 I expected a much better product.