Over a quarter of all UK mobile phone customers are not satisfied with the service they receive from their operators, according to a survey of 3,000 customers by Ofcom.
The watchdog's Quality of Customer Service report said that Three performed the worst of all, with just 63 per cent of its customers happy with the service they receive.
O2 and T-Mobile customers are the most satisfied with scores of 72 per cent each, while Orange came third on 70 per cent and Vodafone and virtual mobile network operator Virgin Media recorded 69 per cent each.
The mobile sector also scored worst in dealing with faults and repairs. The report said that 20 per cent of respondents claimed that their problem was never resolved.
The figures suggest that, while phone companies are keen to get customers signed into 24-month contracts, they are not so hot at providing strong support for the duration of the contract.
It's not much better with broadband providers. BT on a 57 per cent satisfaction rating, and Virgin Media on 56 per cent, indicate that the battle for headline speeds overshadows long-term customer care.
Orange scored the best for broadband delivery, hitting 76 per cent satisfaction, followed by BSkyB on 60 per cent.
Orange's position at the top is notable as the firm came bottom of the 2009 survey with just 42 per cent. That position is now occupied by TalkTalk/Tiscali, which achieved just 52 per cent satisfaction from those surveyed.
Ofcom hopes that the research will prove useful to people trying to decide which firm to choose for key services such as mobile contracts and broadband internet.
The regulator added that new rules making it easier for customers to switch providers should also help.
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