A BSA member showed that complaining can make a difference when he tweeted about an insensitive advert.

A NatWest advert read: ‘Making sure your start-up doesn’t stutter’.
A British Stammering Association member put on it on Twitter tagging @NatWest_Help. The tweet invited feedback from people who stammer, which was negative.
Natwest responded: ‘Following your feedback yesterday, we wanted to let you know that our Advertising team are currently amending the digital billboards and the print billboards will change soon too’.
Soon afterwards the digital advert had changed.
My comment
This is not the type of thing one is likely to try and take to court. (If someone did, various legal issues would arise).
However it illustrates that it can be well worth complaining against negative portrayal of stammering, and you can use social media for this.
Also well done to Natwest for listening to the feedback and changing the advert promptly.