According to the FIA, Renault "did not dispute" that the brake bias display changes automatically, but insisted that the drivers use buttons to actually change the settings.
In their decision, it noted that the disqualification is a more severe punishment for being found in breach of Article 27.1, which states a driver must control the auto alone and aided, but the potential advantage from the system Renault was running is greater than more recent cases.
It was one of Renault's best results of the season at the Japanese Grand Prix but their delight was short-lived when Racing Point lodged an appeal into their braking system.
The statement said: "We regret the Stewards' decision and, in particular, the severity of the sanction applied".
The stewards concluded that the system "used innovative solutions to exploit certain ambiguities" and did not breach the technical regulations.
"In our opinion, the penalty is not proportionate to any benefit the drivers derived, especially when used within the context of a system confirmed fully legal and innovative", said Renault.
The governing FIA said in a statement ahead of the Mexican Grand Prix that Renault had until Thursday to appeal the decision.
'It is also inconsistent with previous sanctions for similar breaches, as acknowledged by the stewards in their decision, but expressed without further argumentation.
After further submissions from both Racing Point and Renault, the FIA Technical Department carried out an analysis of Renault's software and data and held a further hearing via teleconference on Wednesday.
Renault do not agree with the verdict but will not take the matter any further, stating they did not wish to engage further in "sterile debate".
"Nevertheless, it is still an aid and, therefore, contravenes [the regulations]", the race stewards stated.
Exact details of how the system works has not been published to protect Renault's IP, but the stewards found that it "acted as a driver aid, by saving the driver from having to make a number of adjustments during a lap".
Lance Stroll and Daniil Kvyat will now be classified in ninth and 10th respectively from the Japanese GP, while Charles Leclerc, Pierre Gasly and Sergio Perez move up to sixth, seventh and eighth.