Bookmakers Ladbrokes is refusing to pay out more than £7m to a Southampton man who gambled on a white Christmas across the UK, as the bet was accepted by mistake.
Cliff Bryant, 52, had placed two £5 accumulator bets that snow would fall on 24 towns and cities across the north of England on Christmas Day.
"We have apologised to the customer for any confusion and for mistakenly accepting an accumulator bet when our rules state only single bets are available on a market of this nature," said a spokesman. "We are happy to void the bets and to pay the customer his winnings on the relevant singles."
They however amount to just £31.78, rather than the £7.1 m Bryant was expecting.
The graphic designer, who said he was "gutted" and would seek legal advice, claims the first accumulator would have won him £4.9m, with the second adding £2.2m.
"If I make a mistake in my work like that it costs me dearly and I think the offer should be a lot more generous than they have made," he said.
Ladbrokes should have made their rules clearer, he added.
"They are one of the leading bookmakers in the country and they ought to do their homework a bit better in future."
Bryant has contacted the Independent Betting Adjudication Service (IBAS), an impartial adjudicator on disputes that arise between gambling operators and their customers.