John and Jane Mitchell, from Dartmouth, say it is not fair they are having to fork out �4,000 to repair the damage.

South West Water (SWW) has refunded this year's sewage charges to the couple as a "goodwill gesture".

But it said the sewer blockage was caused by people's "irresponsible" disposal of fat into the sewers and it was not liable for the damage.

You feel as if your home has been soiled John Mitchell

Pensioners Mr and Mrs Mitchell were sitting in their home after lunch, when they heard a strange gurgling noise coming from their downstairs loo.

They went to investigate, and to their horror found a fountain of sewage erupting out of the toilet.

Mrs Mitchell said: "It was shooting up in a torrent. I lost my cool and screamed. I thought the next thing will be a rat.

"We knew it must be coming from the main sewer, not our sewer.

"We had never had any problems with our sewer. It was absolutely ghastly. The smell was really offensive."

'Lack of care'

The eruption continued for half an hour and flooded the couple's utility room, hall, sitting room and dining room.

Mr Mitchell blamed SWW for a "complete lack of care and attention".

"I think they should pay the cost of putting our home back to normal," he said.

"It's a bit like having burglars in your house. You feel as if your home has been soiled."

Steve Bird, SWW operations director, said the company offered a clean-up service to customers affected by sewage flooding, but it was not liable for the damage.

"We are very sympathetic to their plight, but the cause of the blockage was the irresponsible disposal of fat into the sewer," he said.

"We operate and maintain the sewers on behalf of our customers but we cannot be held responsible if people dispose of things irresponsibly."