Cyclosa: some buttons stopped working, did I broke it?

So I had the cyclosa bundle, the one that comes with abyssus mouse. I know they're the cheapest on the razer family, but I really like them, the mouse already got kinda broken so I buyed the same one again. But now some buttons on cyclosa stopped working, "d" "0" and "-" are absolutly dead so I can't use it anymore. Keyboard is clean by the way, I even got it completely open to check the insides, doesn't look like there's something wrong with it though. I might have this keyboard for 3 years now, or more, so I don't think I can request warranty on it (and there's the thing I live in Brazil too, razer warranty probably doesnt even work here). I just wanna know, sincerelly, from you all bc this have been bugging me: Did I use it wrong and got it broken or is kinda normal for it to just die in '3ish' years? Should I at least try to get it repaired or is not worth it? Here where I live they're not that much cheap and prices are rising every day now, for the price I payed on it and the quality promissed I thougth it should work for a little longer. Sorry for any english mistakes as this is not my mother language, hope I can at least make myself clear here lol