Dark clouds that can linger after holidays from hell

But half of those who aired their grievances were left feeling disgruntled about the outcome, the study by Which? Legal Service found.

One third found it difficult to complain while half felt fobbed off by the company or person to whom they complained.

Eight per cent even considered starting legal proceedings in order to get their complaint heard, according to the consumer group.

Joanne Lezemore, a solicitor at Which? Legal Service, said the nature of the complaints was varied. "We get people ringing about cruises that haven't stopped at all their locations, which is a major issue for people," she said.

"Then there are people who turn up at their hotel and find half the services advertised aren't there or that it's been advertised as a five star hotel when it's actually only got two stars."

The fall-out of the volcanic ash spewed from an Icelandic volcano that grounded thousands of flights earlier this year is still plaguing holidaymakers, who are experiencing difficulties in getting their money back, she added.

In one recent holiday from hell, a woman who had booked a trip away to celebrate her 50th birthday was distressed when traders came into her hotel and threatened guests who refused to buy their goods.

Which? advised those who have a problem with their holiday accommodation or resort to raise their problem and the effect it is having on their holiday as soon as possible with the holiday company's representative.

They also should obtain a complaint form, fill it in, get the representative to sign it and keep a copy as well as taking photographs or make notes of the problems in case they need evidence later.

Other advice is to get the names and addresses of other holidaymakers who can support them and act as independent witnesses and write to their holiday company when they get home if the problems are not resolved satisfactorily.

Which? chief executive Peter Vicary-Smith said: "We all look forward to our holidays and the last thing anyone wants is to have to deal with problems when they're supposed to be relaxing and having fun.

"Unfortunately our members tell us that they're often made to jump through hoops when trying to complain to holiday companies, having to write multiple letters and struggling to get a response."