Hi Billy,
Yes you can absolutely ask them to remove the videos associating you with their business, however whether they comply is another story. Australia has no specific law aimed at preventing the unauthorised use of your image however there are some broad principles of consumer / commercial law that may apply in this case.
If you created the pictures or the video or otherwise own the copyright in the videos and pictures then obviously by posting them without your consent would be breach of copyright. However, assuming that they own copyright in the videos they are using, you still have a few options.
1. Misleading and deceptive conduct under Australian Consumer Law - if you are a celebrity or well known in your area of business, your former employer may be engaging in misleading and deceptive conduct by continuing to display your image in videos associating you with their brand. This generally only works however if you are a celebrity or fairly well known;
2. The law of passing off -
It is useful to protect an individual or business against a deceptive misappropriation of its reputation by another business. To establish "passing off", you must prove that you have some reputation, and that your former employer is making some misrepresentation which causes or is likely to cause damage to you. Again you must establish you have some level of business reputation to successfully bring this action.