Not to be a Debbie Downer, but I regularly rent cars from Dollar as they are significantly cheaper than the main companies, but still located in the airports, however their fleet is on the older side and many of the cars smell so I have to go from car to car to find one that does not smell. The customer service desk is hit or miss and phone support is all but worthless. If pre-paying, which is how you get the ridiculously low rate they offer, be warned that you have to show them the credit card you booked with before you can get the keys. I forgot my card one time and it was over an hour until someone got permission to change the reservation to one of the cards I had with me. Totally my fault but one would think that a substitute card would be trivial to take.
I had another time where my CC was compromised after I had reserved the car, but before I picked it up. That too was nearly impossible to fix since the rental desk cannot take or modify rentals involving a different CC. They really tell you call customer service to fix anything even though you are talking to them in person. They fixed the CC issue by taking another card, but they worked me over by not telling me switching cards removed the pre-pay rate to the pay at pickup rate. No mention of the change and no paperwork emailed. I found out at return when the amount did not match what I pre-paid. Customer service could not do anything so I went to Twitter and it was fixed.
I can take responsibility for the first problem, the second could happen to anyone, but the third is real winner. Pre-paid for the rental like I always do and that there not any cars in the class left. Back to the customer service in the airport because they cannot approve a class change nor can they do it. Waited in line again, and there is always a line because they have inadequate staffing, and the class was changed to one with plenty of cars. Bait and switch again. Got me with the pay at pickup rate at the higher class price. I caught that one at the desk.
Throw in the website is circa 2000 though there have been a few modernizations. I would equate the level of service of most of the employees to be that of the "Pop Copy" employees in the Dave Chappelle skit. Two out of three December rentals were successful the other was fixed before I left the desk. Headed to CA next week and went with Avis as it was less than $50 difference between the one week rentals.
My point is bringing one of their cars back less than full (T-Mobile Benefit) and thinking there will not be hurdles is the definition of insanity. You will be able to get it fixed, but it will not be easy. I will not quit using them because they are always significantly cheaper than every other on airport rental car company. On the upside they generally do not even look at the car for dents and scratches when you return it.