It was billed as a “celebration of chocolate in all its delightful forms” but ended up a tragic tale worthy of an Oompa-Loompa song.

Police were called to a venue in Glasgow last weekend after furious families who had spent hundreds of pounds on the Willy’s Chocolate Experience complained about the “awful” event that left children in tears and was abruptly cancelled midway through.

The event organiser, House of Illuminati, which charged up to £35 for tickets to the immersive experience, promised a “celebration of sweetness and imagination” based on the Warner Bros film Wonka, starring Timothée Chalamet as the young chocolate entrepreneur, which was an instant hit with children and grownups over the festive period.

The event publicity promised giant mushrooms, candy canes and chocolate fountains, along with special audio and visual effects, all narrated by dancing Oompa-Loompas – the tiny, orange men who power Wonka’s chocolate factory in the Roald Dahl book which inspired the prequel film.

But instead, when eager families turned up to the address in Whiteinch, an industrial area of Glasgow, they discovered a sparsely decorated warehouse with a scattering of plastic props, a small bouncy castle and some backdrops pinned against the walls.

After an immediate and angry response from early arrivals who demanded their money back, organisers called a halt to the event only hours after opening, but failed to inform later attenders, some of whom had travelled substantial distances and are now demanding their train costs be refunded too.

AFacebook group has been set up by furious families, who described their children crying with disappointment at the event which was scheduled to run on Saturday and Sunday and lambasted the event as a “farce” and the organisers as “cowboys”.

Police Scotland confirmed that officers had been called to the venue after complaints.

Paul Connell, an actor who had been hired by the company to perform at the event, told STV News of his shock when he arrived at the warehouse and realised that the rubric he had been given was impossible to fulfil because none of the promised props or special effects were there.

“My heart sank looking around … I just felt sad because I was aware of how many kids were going to be coming through.

“We were told to hand the kids a couple of jelly beans and a quarter cup of lemonade at the end.”

Connell said that when he asked the organisers what he should do with the script he was told to improvise.

In a statement, House of Illuminati apologised to customers for the “very stressful and frustrating day”.

“Unfortunately, last minute we were let down in many areas of our event and tried our best to continue on and push through and now realise we probably should have cancelled first thing this morning instead,” it said.

The organisers confirmed that full refunds would be given to customers, which could take up to 10 days.

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