With Debit cards the POS debits your account for the $75.00 or whatever the limit is. After the sale is complete it makes an adjustment. That adjustment may take some time. Disconcerting if you check your bank account shortly after a $50.00 fill up.
You can stick it back in if you need more. It debits your account again. You can do this as often as you like as long as you have sufficient funds to cover the max each time.
Do not try using your debit card at the truck pumps. They try for large number like $500.00 which gets your bank real nervous, real quick. Don't ask how I know.
If there are diesel pumps at the retail side of truck stops, they are usually cleaner and usually give the cash price.
Credit Cards are another matter.