WhatsApp users have complained to European Union consumer groups of being bombarded with pop-ups to accept the app's new terms of service over a new privacy update. Complicating matters, the privacy update for the messaging service has confused many users.

The European Consumer Organisation (BEUC) on Monday filed a complaint with the European Commission against WhatsApp for breaches of EU consumer rights, it said in a press release.

There is reportedly confusion over whether the update allows Facebook to gain more access to users' private information and permission to share it with other group firms. WhatsApp was acquired by Facebook in 2014 for $19 billion.

The BEUC's complaint sent to the EU’s Executive Commission and the bloc’s network of consumer authorities.

“WhatsApp has been bombarding users for months with aggressive and persistent pop-up messages to force them to accept its new terms of use and privacy policy," BEUC Director General Monique Goyens said.

“They’ve been telling users that their access to their app will be cut off if they do not accept the new terms. Yet consumers don’t know what they’re actually accepting."

The complaint states that WhatsApp executed the changes to its terms of service and privacy policy in a nontransparent or easily understood way.

"BEUC’s action is based on a misunderstanding of the purpose and effect of the update to our terms of service. Our recent update explains the options people have to message a business on WhatsApp and provides further transparency about how we collect and use data," WhatsApp said in response.

“The update does not expand our ability to share data with Facebook, and does not impact the privacy of your messages with friends or family, wherever they are in the world.”

WhatsApp reportedly has over 2 billion users.