Well i had a problem with my air fuel ratio gauge and it was just over 2 years old.
Started to get the digits missing and wasn't happy as i couldn't read it. So i spoke to stack and they told me to go through the dealer i bought it from, which was Merlin Motorsport. Another good company. They sent the gauge off and Stack said i will have to pay £35 to get the problem fixed, which isn't bad for a £230 gauge! They then got back in touch and said they will fix it as a good will gesture.
In the end they said it wasn't repairable so they sent me a brand new gauge. Couldn't of asked for a better service really.
If anyone has a similar problem in the future, dont do direct to stack cause they will just tell you to go to the dealer you got it from. Seems a bit pointless when it goes to them in the end anyway.