Took my £40 pressure gauge and gas back to halfords told them it was faulty and got my money back. Total cost for messing for 15 mins and regas of £70.
My advice as said go to the garage. However, also don't go to halfords their units simply don't work.
Glad you got it all sorted in the end and got your money back from Halfords.
What did i say in the first place