Budget - Couple general questions

Hi, I rent pretty regularly from the St. Louis Airport location and I was coming in Monday for a one night. The rates for a one day rental started around $70 with a Tuesday dropoff but if I rented on Sunday the rate is only about $30 for the two days. They supposedly keep the reservation good for 24 hours but would i be hit with the higher rate regardless if I pick it up on Monday within 24 hours of the original pickup time. I was able to reach a counter person who was very helpful at the STL location and she said they would probably black out the original rate and hit me with the higher rate due to the change in pickup time. Sounds ludicrous that they charge you twice the amount for 1/2 the rental but probably unfortunately true. Anyone have any thoughts on that? Also, this leads me to my second question, just how accurate are the counter people in describing policy. For example, the website says one thing and what actually happens is another. If I have a non-prepaid rental that I don't keep the website says you get hit with $50 charge. The counter people though have told me not to worry about that and I've never been hit with it when on the few instances I've been a no-show on a non-prepaid reservation. The website also says their is a 29 minute grace period on rentals, the counter people have told me their isn't one anymore. So who should I believe, the counter people or the website???

Thanks

The lower Sunday pickup price might be a weekend rate.