Buying a commodity with a currency and receiving the change in another currency

Q 2: Some people sell soft drink cans and mineral water glasses for banknotes as they are more beneficial to them and give the remainder as coins so that the buyer uses them for calling from phone booths. What is the ruling on this? Is it permissible?

A: It is permissible for a person to buy some commodity, water, juice or whatsoever, from a trader and take the remainder as metal coins immediately to use the coins for calling from phone booths. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.