In Hamilton experienced situations where I had to clarify to the cashiers at POS that change due is different than giving money. Change due (change back to customer) occurs when a buyer pays for the item with cash amount more than the price of the merchandise (exact amount not at hand).
Giving money has different meanings, change due is not the same as giving money.
Some merchants offer the facility of CASH BACK (no fee withdrawal from a bank account) as a covenience so customer can get some cash at POS instead of going to the ATM machine. This cash back comes out of customers bank account or credit card etc. and is shown on the receipt and requires customers initials.