Pokemon infected heart gold and soul silver

me and my friend wanted to buy pokemon heart gold and soul silver about 5 months after it came out. We went down to the video game store and bought heart gold and soul silver. I got soul silver and he got heart gold. We went to my house and started playing them on our ds'es and my friend used a gameshark and when he tried to use a code the game ran up with a text box "Dont Cheat In My Game" and then we both had the same saves on our games named "Play!" so as we tryed them out the game was nothing like we saw in the adverts. parts of the body was missing. and we had 6 pokemon but none where following.

As we both got to lavander town a message poped up saying "Welcome To My Town" so we tried to leave but there was an invisable wall. We decided to turn the game off and make a new one. Then when we was getting our pokemon we both chose cyndaquil. As we got to our rival battle both our cynaquils health was at 1 and the rivals pokemon fainted as soon as the battle. As he said his battle ender he started flashing and there was a screaching noise and we saw the message say "I Said Don't Cheat On My Game". Then after the battle we ran down to the pokemon center and No-one was in there. so we ran down to the nearest town. And we found the pokemon center. When we got in Joy was there but she had blood all over her and blood in the pokemon center and we spoke to her and engaged a battle with her and it said "Red would like to fight" But the avatar was all black and white. He sent out a level 100 celebi and our cyndaquil was at full health. So we tried to use an attack but celebi used perish song and they both died straight away.

At this point we where both really scared and then the battle ended and our game reset. These events Kept on happening and we had no idea how to fix this so in the end we just crushed cartrigdes and never played pokemon heart gold and soul silver again.