Was told McDonald's Vincent is no Franchise served slop chips

On the 3rd of June 2023 my family and I visited McDonald's in Vincent Devereux East London. Thee worst service ever they mixed up the order we requested vegetarian was given chicken the fries are nothing like McDonald's fries I mean they were slop chips and cold without salt. We tried asking if there was a problem with a deep frier or salt and asked about the chicken served. They didn't know or understand what we meant about the vegetarian pattie substituting chicken. The manager said they are not a franchise they running their own show. The time was 16:00. Beware their service is the worst from being the best