Dollars thrifty car rental

I have hired a car from dollar thrifty car rental Las year on the 22 December 2020 for 9 days I have returned the car back the next day because the trip was canceled they told me I will get my refund in the 7 to 14 working days after 14 days I call them to find out if they have refunded my money back they told me they have already refund the money in to my credit card on the 11 January 2021 but I have never received any cash from dollar thrifty car rental in my credit card. I have been call them almost every day to inquire about my refund. I keep getting some story that they have refunded me but money still not in my bank account after a month. I want my money back and I will never use your services again and I will never recommend you to anyone. What do I have to do to get my money back. Hard earned money.