Help Needed

Had a dodgy signal on my 3g so I tried a couple things with no luck and eventually opened up the iphone to have a look inside. I noticed that where the sim tray is supposed to push down the golden pins it wasn't pushing down the pins far enough to get the sim to work properly so I stuck a small piece of cardboard in between the pins and the sim card tray which actually worked! However surely it can't be good having a piece of cardboard sitting in my iphone where it shouldn't be and it also means the sim tray sits slightly out of the casing as it can't go all the way in so has any one had this problem and found a better fix?

I would do but it's no longer under warranty