Faulty Clearo Coils

Bought a pack of coils about a month or so ago at Dischem Carslwald. Two coils work each for about two weeks before having to be replaced. The other three in the pack don't work at all. They are sealed in the pack but don't work at all. Not even for a day or two, from the moment they are inserted. This is not the first time I have had two or three other coil packs that had the same problem.