Guy stop buying bulk niche related comment services from new service providers . Because most of them are using software to complete this task and comments made by this process moves into spam section in wordpress blogs (And your blogs will be seen as spammers)
In my wordpress blog I have noticed one good blog whose comments were moving in to spam section . I contacted the blog owner and asked them that are you posting these comments and they replied that they have hired a link builder for blog commenting process . I told them that I have already deleted you 5 comments but everyday find new comment from your url in my spam section . Now they have stopped using that service provider services .