http://www.safeneedledisposal.org/Personally, if you can't find a legit way to dispose of them... then I really don't see as how you have any other options beyond throwing it away anyhow, or else holding on to it indefinitely until or unless you do find somewhere that will take it off your hands and get it out to these special 'collection centers'.... which is pretty inconvenient and unlikely to actually be done by very many.
And just in case this can help you or anyone else, what I personally do with my needles and because I can simply re-cap and then remove the needle from my syringe barrel (no breaking off, cutting etc. Just one more reason I love luer locks), is that I simply throw away the syringe barrel but I then put only the re-capped needles (since they're my own, no reason not too) into my sharps container. The result is that after a year and three months (my dose schedule is fortnightly) I am not even remotely close to it being full and we're talking about a fairly small container here... it is smaller than a full size coffee can. Seriously, I am more likely to use it up faster with my double edged razor blades than I am with my needles. Apparently razor blades command the use of sharps containers almost nation-wide too now, so win-win I guess.
Yeah so... if you do figure out what to do with them other than throwing them away, and proper/legally mandated disposal does cost money where you are and without any free place to turn them over to, this should save a hell of a lot more money than if you were to throw away syringe and needle together. It will probably take me half a decade to fill mine up lol.
Further, and still in the scenario of no proper disposal options, this method also decreases the odds of someone misusing your gear because there won't be any syringe barrels in there with the needles and the likelihood of them finding just the right syringes to work with those needles would be frankly astronomical. Again too, if you re-cap the needle first, that would better circumvent wildlife being inadvertently and negatively impacted if you did have no alternative but to throw them away in the trash. And yeah, I also agree that taping it up first would be good.