@safeqaz all TFL's parking PCNs are currently open to challenge, but you've given us nothing to work with. As John says, please read the guidance
here and re-post the PCN with the PCN number and number plate visible.
Also please call TFL tomorrow on 0343 222 3333 and ask for the video, they will send you a DVD in the post and put the penalty on hold while you wait.
Lastly please give us a link to the exact spot where this happened, the guide I've linked above will explain how to do this.