Train firm Southeastern has apologised to a family after a series of mix-ups left them paying more than £100 extra for fares - and then being given tickets 500 miles from where they wanted to go.

Mark and Rebecca Simmonds had driven from their Sheppey home to Sittingbourne station to buy a ticket to Thurnscoe, near Barnsley, South Yorkshire.

The couple were heading up there with their youngest daughter, five-year-old Georgie, to buy a dog.

They had researched the ticket prices online and were expecting to pay about £120.

When they arrived at the booth they were told it would cost £232.70 and when they queried the price, they were told this was definitely right and they must have looked at the wrong section.

Eventually they paid the extra cost and boarded the 10.37am train last Tuesday.

It was only when the ticket man came round they realised they had been sold tickets to Thurso, which is the most northerly town on the British mainland - home to the country's most northerly railway station and 503 miles away from Thurnscoe.

Rebecca, of Queenborough Road, Halfway, said: "The ticket man said 'you're going a long way, you're not going to get there within a day'. When we said it's not that far he told us Thurso is at the other end of Scotland."

The Simmonds, who have four other children, were advised to stay on the train until St Pancras, where they would be able to get a refund.

But this was refused because it is a different train company which operates in London.

They then had to pay out again for the correct tickets, from Sittingbourne to Thurnscoe, at a cost of £131.20.

There was a happy end to the day though as the Simmonds, who already have one Northern Inuit dog named Timber, eventually made it to Thurnscoe and returned with another dog, which they have named Takarra.

However, they are still waiting for their refund from Southeastern.

Southeastern has apologised for the error and said they can expect a refund as soon as possible.

A spokesman said: "We apologise if there has been a problem in this particular case.

"We are currently looking into this case as a matter of urgency to establish the facts and are working with the passenger to get it resolved as quickly as possible."

Thurso/Thurnscoe factfile

• Thurso is a town on the north coast of Caithness in Scotland.
• The town is often seen as a stepping stone to Orkney, with established
• Many people use Thurso has a point of departure for the best scenic route Scotland has to offer, the 140 miles taking in the north and west coasts via Durness to Ullapool.
• Thurnscoe is a village in Barnsley in South Yorkshire.
• It is one of the many former mining villages in the Yorkshire coalfield.
• Thurnscoe was hit by a flood in June 2007 which burst the banks of all the dykes in the village.