Useless Doom Inserts repellent

Hi. I have always bought Door Multi Inscets Odourless for the many fly's on our plot but I bought 2 cans I sprayed both bottles around my house and closed doors next morning I wake up to just fly's no window or door was open, I can not believe I pay R100 for the can's at no but no relief not one dead fly on ground. I myself is shocked at the useless of the can Doom, use to work I don't know what they putting in can now but definitely not inscets repellent.