Keep reporting, but you need use proper comment why you are reporting that post, otherwise moderators will unable to handle it.
I second that statement, and I'd also like to get an example of how Rambotnic reports posts, i.e., what he writes in the report field. That may not be the problem, but I'd say you definitely have to be accurate with what you write and write it in such a way that it's easily understood by the mods.
And no, it's not a waste of time reporting posts. My advice would be to not look to see if your report got followed through on--when I report a post, I just do it and forget about it. Once I've reported it, the matter is no longer in my hands anyway. Sometimes it takes a while for a mod to see the report; sometimes it never gets seen or handled. Doesn't matter to me, because I've done my part.
If nothing else I get a sense of satisfaction that I at least did something about a shitpost or a post in the wrong section or whatever. Obviously I can't force Rambotnic to see things that way, but I'd certainly advise him not to stop reporting.