Scottish Power has been ranked the worst company in Britain when it comes to how it deals with its customers, according to a new Which? report released today.

The energy company is bottom of a table of Britain’s 100 biggest brands ranked for customer service, with a rating of just 59 per cent. Based on a survey of 3,501 Britons, the report scores firms on the helpfulness of their staff, their knowledge of products and services, and whether they make customers feel valued.

Poorly performing companies make people feel like a nuisance, and are criticised for “inflexibility and long waits,” according to the report. In the case of Scottish Power, customers told of their “experiences of its ‘useless’ customer service and unhelpful standardised replies. One unhappy customer said: ‘They have been incredibly unhelpful, rude and blamed us for a fault they have admitted is their own.”

Telecommunications giant BT didn't fare well (Getty) (Getty Images)

Another energy firm, Npower, is in 99th place; and BT, at third from bottom, is described by one respondent as “the worst company in the world.” TalkTalk is 97th in the table, followed by budget airline Ryanair - at joint 95th place with Vodafone.

Cosmetics company Lush comes out as the best in how it deals with customers, scoring 89 per cent and having a “‘happy atmosphere’ and welcoming staff,” according to the report. First Direct bank is in second place, with a rating of 86 per cent. It is followed by Lakeland (84 per cent) and The Body Shop, John Lewis and Waitrose (all scoring 83 per cent).

Companies risk losing business if they provide poor service, with broadband providers and energy companies among the worst offenders, warns Which? “Long suffering customers deserve better, as once again essential services that we all rely on have been caught falling down on how they treat people,” said Richard Lloyd, the consumer group’s executive director. “Nearly nine in 10 told us poor service puts them off using a company again, so there is a clear incentive to offer service that makes customers smile. Companies at the bottom of our survey should take note: make your customers seethe and you will pay the price,” he added.

Foreign call centres are the biggest source of irritation, followed by automated telephone systems and being passed around different members of staff. The personal touch is what matters most, with more than half (53 per cent) citing friendly and helpful staff as a good example of good customer service. Staff having a good knowledge of the things they sell, and the speed of service, are each cited by 29 per cent.

The 100 companies in the ranking are the biggest firms across six sectors. Of these, personal finance comes out on top – with an average rating of 77 per cent, closely followed by supermarkets and retailers. Travel and telecoms firms are in the bottom half, with energy companies the worst performing sector with an average score of 68 per cent.

Waitrose was rated the best supermarket for customer service (A P Monblat/Creative Commons)

In a statement, a Scottish Power spokesperson said: “Last year all our customer accounts were migrated on to a new IT system, which resulted in a very busy period as disappointingly we experienced more problems with the new system than we would have liked.” The company has recruited an extra 500 customer advisers to its call centres. “We are committed to restoring our service levels to the highest possible standards,” they added.

How major companies fared

Waitrose – Rated the best supermarket for customer service. “I had a problem with a food item - they refunded me five times what it had cost in vouchers, so I was really impressed,” commented one shopper.

Ryanair – The budget airline came bottom in the 2013 survey, prompting chief executive Michael O’Leary to pledge major improvements in the way his airline deals with people. Two years on, it remains near the bottom of the ranking.

Lush – Winner of the first Which? survey in 2013, and runner-up last year, the handmade cosmetics firm regained top spot this year. One customer dubbed it “a great shop in every way.”

Npower – Paul Massara resigned as chief executive last month, in the wake of falling profits after hundreds of thousands of customers switched suppliers over mistakes made with bills.