Standing in a bookmaker’s, Cliff Bryant thought that a heavy snowfall had changed his life forever.
Told by the cashier that his two accumulator bets had come in, Cliff was set to scoop £7.1m.
Now Cliff, from Shirley, Southampton, intends to seek legal advice.
It comes after he placed two £5 accumulative bets on postcodes where it would snow on Christmas Day.
Although he says that he was advised to do so by the cashier, Ladbrokes argues that it was a mistake and that he should never have been allowed to place the bet as an accumulator.
A money-spinning accumulator bet is a series of wagers where the winnings from the first bet roll over to the next and can only be won when all separate bets named are successful.
But Ladbrokes says that according to its rules the bets should only have been accepted as a single bet and therefore Cliff was entitled to just over £30 as winnings.
The bookmaker does not dispute that Cliff was correct in each of his bets, and another bookmaker, Paddy Power, confirmed that he would have won £4,922,800.31 on the first bet and £2,233,492.73 on the other.
The graphic designer, 52, said: “Gutted is not the word.
“This is a genuine mistake and 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.
“Millions of pounds will have been spent on this bet at Christmas. How many of those people will have been allowed to place accumulators?
“They are one of the leading bookmakers in the country and I think they ought to do their homework a bit better in future.”
Cliff has now called on Ladbrokes to make its rules clearer as they were not made obvious to him either in the shop or online.
The Independent Betting Adjudication Service (IBAS) is now investigating the bet.
Danny Cracknell, adjudication manager at IBAS, quoted a section from the Ladbrokes rulebook which said: “Single bets only are accepted, accumulative bets accepted in error will be settled as singles with the stake equally divided.”
Ladbrokes spokesman David Williams said: “We have apologised to the customer for any confusion and for mistakenly accepting an accumulator bet when our own rules state that only single bets are available on a market of this nature.
“We are happy to void the bets and to pay the customer his winnings on the relevant singles.”
Last night an independent solicitor said that Cliff ’s chances of seeing his winnings were slim.
Rick Munro, commercial dispute resolution partner at Lamport Bassitt, said: “Generally speaking gaming bets are largely unenforceable. You rely on the goodwill of the people you are placing the bet with.
“There are some exceptions to this but the general rule is he wouldn’t have a leg to stand on.
“It’s about one of the only contracts in public policy where the contracts are unenforceable.”