Avis doesn't know what their doing

Renting the vehicle wasn't an issue, but we are still waiting for the refund. The car was taken back to Avis on the 17.01.2019. After two weeks, Avis called to ask when the car will be returned?? After going in and showing them the paperwork that the car was returned, did they only go to find in the lot. Seriously unorganized if they can not even keep track of their vehicles. Now, we are waiting for the refund. We went to them twice already and they promised that the money will be paid back in a certain amount of days. Both that deadlines lapsed, and still nothing. Avis is supposed to be one of the top rental companies...but i have used lesser companies, that offered immensely better service and much more organised.