This is a press release from Cotswold District Council dated 9th May 2017.
There are a lot of these sort of scams but this one is of particular relevance to the Cotswold District area.
“A resident in the Cotswolds has received a telephone call from a ‘company’ which allegedly works for Cotswold District Council. He was told that he was due to receive a £6,000 council tax refund because his Council Tax banding has been too high in the past.
The telephone number of the bogus company is 03332 123132.
Please be aware that this scam may be targeting many residents in this area and please do not enter into any discussions with the caller. Most importantly, do not disclose any personal information such as banking details.”