Deposit refund

I am unhappy with the service I’m getting at Avis budget in Montana. My refund keeps being postponed. I returned their car with a full tank and in good condition on the 6th of January at exactly 10am. Before I took the car I asked about their deposit refund and they said 7days, when I returned the car I asked again and they still said 7days. Last week on the 12th of February I called and they said give it 3 more days. I waited. Yesterday the 23rd I called again, the agent said during the course of the week. What is the course of the week?this is not a definite answer and they are not committing themselves. They are strict with the return time but take their time refunding.