Gone badly downhill. I've been getting my annual boiler service done through Vaillant for years. They spammed me in the past, but started behaving themselves after I withheld consent for this under the GDPR. Then out of nowhere they started spamming me again. I made a complaint, which they ignored. I called up hoping to resolve the matter and book an annual service which is now due. What an exercise in futility. Hold times are excessive and make you lose the will to live. Staff have comprehension problems and lie blatantly. They claimed they have no contact details for me when I challenged their data breaches. So it's off the the Information Commissioner we go - and they've obviously lost my business. Had they been professional about their failures, they would have secured a booking today. Instead they can explain their data breaches to the Information Commissioner.