More than 20 short message wireless value-added service providers in Guizhou have signed a self-discipline agreement in Guiyang, the province's capital city, to commit to double refunding consumers when errors occur on their charging systems.

These service providers promise that they will have users know about the details of their service, including the pricing standards, service patterns and method of cancellation before signing contracts with them. In order to make sure that users can easily unsubscribe from wireless services, service providers will also open a 24-hour hotline.

There are more than 500 service providers in Guizhou, and local media reports that all of them have plans to soon sign this agreement.