Gumtree is a spam haven

Why is it that i cant post the same ad again after a week or so?, just to bump it up to the 1st page again. There are many, MANY ads that are repeated multiple times...its sickening to see the same seller with multiple ads spamming the same overpriced items on the first few pages every few hours, one would think that those ads would slowly fade to the later pages as new ads get published but they don't and they are free ads from a private seller!...so there are 3-4 of his/her ads on the 1st page, then the very same ads on the 3rd and 5th page, same ads, same price. gumtree should regulate the repetitiveness of this practice and limit spammers.