In actual accounting terms credit and debit is referring to a reporting account not a direct money relation. I mean sometimes to move money you debit it from one line and credit it to another.
Think of it this way… You have Customer Account A… Ticket total is 200 so you settle using Customer Account A for 200… This means you need to PUT that value somewhere… so it is Credited to the account Customer Account A.
If it was a debit transaction if the accoujnt already had money in it… it would be reversed you would be Debiting it from Customer Account A and Crediting it into something else.