The average time mobile users were on hold rose again in 2021 – to two minutes and 15 seconds. But with O2 the average last year was a tedious three minutes and 59 seconds.
However, Three was the quickest – typically just 16 seconds.
Tesco Mobile and Virgin Mobile reduced their delays in 2021.
But Sky Mobile and Three were the only mobile firms to cut the queuing to pre-pandemic levels.
Ofcom’s Ian Macrae said: “Some companies need to up their game in resolving problems, especially when prices are going up.
“It’s never been simpler to switch, so if you’re not happy with the service you’re getting, vote with your feet and look elsewhere.”