Around 27 per cent mobile subscribers have experienced reduction in pesky calls after telecom regulator Trai's stringent action against unregistered telemarketers, according to a survey by online platform LocalCircles. However, a majority of subscribers said there is no relief yet from pesky callers, instead there has been an increase in robo calls, the survey, which was released on Monday, said. According to the survey report, only 9 per cent mobile subscribers surveyed confirmed net reduction in pesky calls post Telecom Regulatory Authority of India (Trai) blacklisting of spammers. About 18 per cent subscribers confirmed decline in pesky calls but experienced increase in automated and robo calls. "For the first time in this survey series in last 5 years, LocalCircles is seeing 27 per cent mobile subscribers surveyed confirming that pesky calls have reduced, however, of them 18 per cent are reporting an increase in robo/automated pesky calls indicating that regulator must be vigil