Very poor service

I booked a romantic dinner at Alvenston Manor hotel on the 17th September 2018 for the 25th September to celebrate my husband’s birthday. Everything was confirmed on the day I booked but on the 25th September 2018,Eugene,the Receptionist told me that I was not booked but I can only come for just a normal buffet. I was not happy at all because the food was not even great. What has happened to Alvenston Manor Hotel motto? – “Provide the highest standard of service delivery’ Having in mind that that this is a high class hotel, with good star rating, belonging to the famous chain of hotel, I perceive this type of the treatment as unacceptable.