Bosch Condens 1200 W Error 227: Request for Official Service Report

I use a Bosch Condens 1200 W combi boiler and on three different occasions it displayed error code 227. Each time this error appeared, the boiler stopped working and I was left without both heating and hot water. After these problems, I contacted the authorized Bosch service in Burhaniye, Balıkesir. When they examined the device, they stated that the fault was caused by the plumbing, specifically claiming that the condensate drain pipe being connected to the rainwater pipe outside the building was the source of the problem. Despite my request, they refused to provide me with any written form or official service document regarding their assessment and the malfunction. I have also documented the situation with photos of the boiler and its internal parts, and I am ready to share these if needed. I want Bosch and the authorized service to recognize and record the problem with my combi boiler properly and to provide me with an official written report and documentation of the fault and the intervention carried out, so that my rights are protected if the issue recurs or develops into a more serious malfunction in the future.