Crowdfunding website Indiegogo is working with a debt collection agency to recoup funds from Retro Computers’ troubled Sinclair ZX Spectrum Vega+ campaign.

Indiegogo recently agreed to give the Vega+ team a provisional extension, it explained in an update. It asked the team to send it a review console and refund backers immediately upon request. But those requirements apparently weren’t met, and Indiegogo said it’s now working with a collection agency to attempt to refund backers.

“This has been a challenging situation for all involved, and one we thought would be resolved with the backers receiving their game consoles,” Indiegogo said.

The Vega+ is a handheld LCD console that can connect to a TV for home use. It’s based on the ZX Spectrum 8-bit computer released in the U.K. in the 1980s and comes with 1,000 pre-installed licensed games. The Spectrum was one of the first mainstream home computers in the U.K. and reportedly sold over five million units worldwide. It was officially discontinued in 1992, but enthusiasts have continued to release games on it over the years.

The Vega+ Indiegogo campaign raised over £500,000 GBP in 2016, but has apparently struggled to fulfill its promises since then. Backers criticized Retro Computers for its failure to communicate over long periods of time. In a February update, the team wrote that some disgruntled people were trying to damage their personal and professional reputations via a “troll campaign.” It apologized for the “ugly outpourings of horrendous attacks, swearing, personal abuse, harassment, and misinformation” on its forums, and said it wanted to set the record straight over rumors it couldn’t complete the project. It then promised to ship its first batch of consoles to backers in April 2018. But that shipment never happened.

Indiegogo said Retro Computers can still send consoles to backers while the collections process is underway. “We hope that the Vega+ team follows through on their promise, and that any remedial efforts on our part will be rendered obsolete,” it said.