I have noticed a dent in the frame of my chopper bicycle. I've never noticed it before and i've never checked over the frame so thoroughly, I wonder if this could be investigated under warranty? I only weight 56kg and its an adult sized chopper bike. I've never taken it off bad bumps and always took care of it.

The position of the dent is just at the bottom of the headset, but it is slightly angled to the left hand side more than the right. I'm wondering if the position of the dent has been from the frame bending, or whether this could have been a manfacturing fault/in transit.
This is what the bike looks like:
The dent is on the bottom tube, just near the bottom of the headset plate.

This tubing is fairly thick. I would say at least 1 inch thick.
Thanks
Adrian