New camshaft and “klakkert” still!

Mistdreck: Ford KA, EZ 05/2000, bought! 60T down, crackers mowed after test drive, valves were set…nothing….new camshaft in it…nothing! He clacks cheerfully! Eats the control chain??? Should chain and spanner be checked? What else can it be? Am I the only one who hears this??? Used goods dealer (no Ford dealer) is almost gone! Who can help? Guarantee available! Finally give into the hands of a Ford dealer? Who knows each other with the this guarantee shit out? I’m just about to freak out!!!