I pranked my class with cardboard inside chocolate wrapper😅😰(Gone wrong)

I was in class 9th and that day I brought a chocolate wrapper in which I put down cardboard pieces instead of chocolate bar.... I packed that very smartly just like a brand new chocolate.....😎

Me and my friends planned to put that on front bench in lunch and we followed our plan too....
Many boys and girls were talking about that chocolate and thinking whose chocolate that was...Many boys also came to take but they just passed out from there by looking at the same....Some were also planning to take that chocolate....Me and my friends were silently looking at this atmosphere and we were really enjoying that.😆😆...While this craziness was going ....suddenly Our maths teacher came just before the bell rang out.😲😨. me and my friends were stunned to see him...Sir took that chocolate and asked  "whose chocolate is this"....We were silently watching and praying that he shouldn't open that wrapper..😭😱..Then he called peon aunty to take that chocolate and to give that to any child ....We were thanking god to save us ....But then 5 minutes later she came back and said "sir there is cardboard inside the wrapper"...😒😒.Everyone was laughing instead of us....We just frozed for a moment and then we smiled to hide our feared emotions....😞😅
And then sir shouted "who did this"... Everyone noded in refusal...
Sir again shouted" who did this"
Then he asked again and again but nobody replied .....Then he doubted on  boys of my class and he gave a lecture of at least 15 minutes .😑😣..He thought that this was done in order to disrespect him...Then he complained principal sir also...but nobody knew who did that......and from that day I realised not to prank when there is a chance to get catched by teacher😅😉