In a Thursday-released report, the US General Accountability Office (GAO) said that most Americans are apparently dissatisfied with their overall mobile phone service; and the Federal Communications Commission (FCC) should improve its control over the mobile carriers.

Noting that the FCC has no way to gauge the outcomes of the countless consumer complaints that it receives every year, the 65-page GAO report highlighted that terms-of-service contracts and billing happened to be the most problematic area for a large number of complainants.

The report, based on consumer surveys, said that despite the fact that 84 percent of US mobile-phone customers have been reported to be 'very' or 'somewhat' satisfied with their service carriers, most of the mobile users are unaware of the complaint process.

The GAO survey of 1,143 adult mobile phone users found that nearly 42 percent participants desired to switch carriers for different reasons, but refrained from doing so because of the early termination fee that the switch over would entail.

Further, almost 34 percent consumers complained about having received unexpected charges on their bills; and nearly 31 percent said that they had difficulty in understanding their billing statements at least some of the time.

Saying that the "FCC cannot demonstrate the effectiveness of its efforts to process complaints," the GAO report said that "while the percentages of dissatisfied users appear to be small, they represent millions of people."