Despite being a longstanding customer on planned delivery, refused to deliver recently claiming the tank needed replacing. This was done by shoving a note through the door. No attempt was made to speak about this or to offer any advice or evidence, or speak about replacing the tank. Strangely enough they’ve waited until winter to do this rather than in the summer when there would have been more time to resolve it, leaving a vulnerable pensioner with less than two weeks heating oil and no time to fix it. Despite sitting on hundreds of pounds of money they’ve taken in direct debit for the oil, you can’t actually speak with anyone at Certas as there’s never anyone to answer the phone, and they don’t call back. Truly awful service. Avoid.