ROFL...oh this sounds like it's gonna be funny...
First off, what kind of RAm did you get? Give us the specs!
Second, got pics?
Third, size isn't always important (this applies to sex, too...) Anyway, different manuf's make chips slightly different. Also, over time, the RAM sticks have gotten smaller.
It's also possible that you ('s******, LOL') bought laptop or PDA RAM...and dude...we'd have to club you for that...ROFL