Last week was my second rental from Dollar at DFW ...

Last week was my second rental from Dollar at DFW because they were the cheapest. My organization is very cost conscious but I will not rent from them again. For the second time, I waited nearly 10 minutes before the (very nice) man was able to check me out but my return was even worse. One person was working on a Friday afternoon to check in cars. After an interminable wait while he checked in the car in front of me, I asked him to simply check me in and email my receipt. When the receipt arrived I had been charged (erroneously) $18 for fuel. I called Dollar, explained the situation and volunteered to email the gasoline receipt documenting the refill minutes before the return at a station a mile away. The person on the phone said he couldn't reverse the charge. He transferred me to Customer Service where that person told me I should have complained at the time I returned the car. I explained that I was unable to wait; he reiterated that my complaint was coming too late. After much back and forth, he finally agreed to reverse the charge but said he could not send me a new receipt - I would just have to watch my credit card bill for the credit. This is only the second critical online review I have ever written and probably still would not have done it except that Dollar has now sent me three emails asking me to review them.