Merchant would like the device to pre-auth the amount-- which it does-- but instead of charging the customer a separate amount, and then refunding them the pre-auth amount, he would like to have it just refund them the amount that was not used by the customer.
Merchant explained that with the current way, it is causing his customers to call him thinking that they were double charged.
Lanny Ross commented
Allow the system to post and keep track of transcations against the pre-authorization. Example
$150.00 authorization: patron then orders drinks with value of $30, then later for $50. Bartender can see that he has received $80.00 of transactions against the $150.00 auth.