Deposit refund

My husband and I rented a car with them we brought the car back on Monday the 21st of December. We were told that it takes up to seven days for deposit refund. We understand that public holidays and weekends don't count but today is the 7th and still they did not refund the money I phoned this morning they said money will be in today I must go check I went to check again still no money. When I called them I was told to wait another 4days but why would they do that to us. I will never rent a car from them again and none the people I know will rent from them in other renting companies within 3days u get your deposit back. This is very wrong