Pop star Rihanna urged fans on Thursday to delete Snapchat after the social media app ran an ad making fun of her 2009 beating at the hands of then-boyfriend Chris Brown.

Shares of parent company Snap Inc. were down almost five per cent on Thursday, and were changing hands down almost four per cent at $17.20 a share when markets closed on Thursday. The shares are now worth about the same as what they were priced at when the company first went public in an IPO last year.

"SNAPCHAT I know you know you ain't my fav app out there! But I'm just trying to figure out what the point was with this mess!" the singer reportedly wrote in an Instagram post on Thursday, one that appears to have since been deleted.

Rihanna responding to Snapchat's ad. I can't believe they did this. <a href="https://t.co/TpHQIXTm4j">pic.twitter.com/TpHQIXTm4j</a> —@GNCordova

"You spent money to animate something that would intentionally bring shame to DV victims and made a joke of it!!!," she said, referring to domestic violence.

"Shame on you. Throw the whole app-oligy away."

The Wild Thoughts singer, 30, was speaking out after Snapchat earlier this week apologized and took down an ad on its platform for an online game called Would You Rather! that showed pictures of Rihanna and Brown with the captions "Slap Rihanna" and "Punch Chris Brown."

R&B singer Brown pleaded guilty to assaulting Rihanna in 2009. The attack made headlines around the world when a photo of Rihanna's bruised face was released. Snapchat said in a statement earlier this week that the ad "was reviewed and approved in error, as it violates our advertising guidelines" and was removed on the weekend.

Snapchat apologizes

Snapchat on Thursday said the ad was "disgusting and never should have appeared on our service."

"We are so sorry we made the terrible mistake of allowing it through our review process. We are investigating how that happened so that we can make sure it never happens again," the company said in a statement.

Rihanna's comments were the latest bad press for Snapchat. Its shares lost about $1.5 billion in market value in February after social media celebrity Kylie Jenner, who has some 105 million Instagram followers, tweeted that she did not like the Snapchat site's redesign.