Plumb World in Evesham

Their products are definitely good value and their deliveries are reasonably quick, but behold you if there is a problem.
Their Customer Service department is the worst I have ever encountered in 50 years of work. Their "automated" IT system lies to you, and sends you multiple confusing emails. It cancels your order for replacement parts or back orders if you don't pay within minutes. Just pray it all goes well - it's a leap of faith.