Customers are fed up with being told they are getting poor service “because of Covid”, according to research.

Firms are being accused of using the pandemic as an excuse for long waits on the telephone or late deliveries, the UK Institute of Customer Service said.

It said that consumers were initially tolerant of delays and other issues as businesses fought to cope with the effects of the crisis.

But it said a blanket excuse was no longer sufficient.

The number of complaints about poor service in the last six months was at its highest level since 2009, according to the institute’s survey of 10,000 people.

The sectors with the biggest issues were transport, local public services – such as GP surgeries, councils and police services, and telecommunications, the survey suggested.

A quarter of those asked said that some organisations had used Covid as an excuse for poor service.

“Saying ‘because of Covid’ is not a good phrase,” said Jo Causon, the institute’s chief executive. “Organisations must not hide behind this blanket statement.”

She said that many businesses had responded admirably to the difficulties created by the pandemic. She said that managed queuing systems, such as inviting people to call at quieter times, was one area of success.

Others had gone out of their way to assist people during the crisis, she said. Delays in deliveries had also arisen owing to the container ship that blocked the Suez Canal in March, and border issues as a result of Brexit.

Retailers needed to be honest with customers when they started looking at a particular product about any potential delays, she said, so they were aware of how long they might have to wait to inform their decision about what to buy.