Mobile phone subscribers are annoyed with various promotional advertisements in the form of messages frequently. Despite the earlier policy of launching 'Do Not Disturb' or DND services to stop these annoying messages or campaigns, telecom operators have been reluctant to do so.BTRC, the telecom regulator, has taken the initiative to launch DND services after announcing strict action against telecom value-added service (T-VAS) service providers to protect the quality of customer service.From now on, customers of four mobile operators will be able to activate DND services by dialing shortcodes, the regulator said. Grameenphone subscribers can dial *121*1101#, Banglalink subscribers can dial *121*8*6# and Robi and Airtel subscribers can dial *7# to launch DND service.Md.Zakir Hossain Khan Deputy Director (Media) of BTRC said that this facility has been introduced so that the customers can stop the campaigns which they find annoying.Earlier, during a recent inspection of 11 TVAs , the regulator found evidence of various irregularities. The BTRC said that legal action is being taken by the commission against the companies soon to protect the interests of the customers and such inspection activities will continue.