Kosi, I am moderately knowledgeable about computer tech. If you're having two different sets of RAM go bad that quickly, it is quite possible that you have an unstable power supply. RAM chips are designed to operate in a predetermined voltage range, and if the power supply is fluctuating out of these safe ranges, it can damage your electronics, badly -- and not just your RAM chips.
That being said, I see four primary possibilities related to your power supply. I'd check the power supply in your house, as well as the power supply in your computer.
1) If it's the power supply in your house, buy a good surge protector that also regulates the incoming voltage. I believe newegg.com has a surge protector with a voltage regulator for under $50.
2) If it's the power supply INSIDE your computer, then you've got to replace it, pronto, before it fries more parts.
3) It could be that your motherboard is routing power to your RAM chips incorrectly, which could also result in the isolated damage to that one computer compontent.
4) It could also just be that you had really really bad luck with RAM chips.