TalkTalk and BT have received the worst customer satisfaction scores in a survey of 12 broadband providers.
They scored 38% and 45% respectively with their customers, while Sky (48%) and EE (49%) came close behind them in the Which? survey of 1,800 people.
Frequent price rises, connections that drop, unreliable speeds and "woeful" customer service all contributed to the scores, the consumer group said.
The four account for almost three-quarters of the UK broadband market.
BT alone accounts for almost a third of the country's broadband connections.
Zen Internet had the highest customer rating at 86% in the survey, followed by Utility Warehouse (81%), John Lewis Broadband (68%), SSE (66%) and Plusnet (65%)
Virgin Media (52%), Vodafone (50%) and the Post Office (48%) were also included.