Vodafone has once again been ranked as the UK's least popular mobile network.
The operator finished bottom of the latest survey from consumer watchdog Which?, marking the eighth year in a row it has achieved the unwanted title.
Giffgaff was voted the UK's best provider, with fellow small operators Utility Warehouse and Plusnet Mobile scoring highly, but EE and O2 filled the bottom three places alongside Vodafone, which has now finished bottom in all eight of Which?'s annual reports.
Thirteen UK mobile network providers were included in Which's survey of 6,135 members. The watchdog says it aims to highlight the best network choice for consumers in the UK, including areas such as customer service and value for money.
Vodafone saw one-star ratings for customer service, value for money and technical support, with one in five of its customers telling Which? "customer service, including complaints handling and the way their queries were dealt with, was poor".
Vodafone apologised to users for its poor showing, saying it was sorry customers were unhappy and that it was, "working hard to understand the issue and what more we can do."
In contrast, Giffgaff customers said the network was "good or excellent" value for money.
"The continuing reign of smaller networks over the big players goes to show exactly how important customer support and value for money are to mobile users," said Natalie Hitchins, Which? head of home products and services.
"If you think you're paying too much or are not getting the level of service you expect from your provider, you should shop around for a better deal - you might find you save yourself some money and probably a lot of grief, too."
Earlier this month, EE was named as the UK’s best mobile network according to analysis from OpenSignal, which said the operator had the fastest speeds, lowest latency and greatest availability of all four major networks.