Manager treated me like a ********

i bought a cold drink on friday, 22 May 2015 at Spar Hillcrest and needless to say when i paid for it, i left the receipt on the counter not thinking that i will need it as i had paid the full amount with no change required. I did not anticipate what was to happen next as the cashier did not tell alert me that i had left the receipt behind as it will be needed by security at the door. the manager who is (nigerian) stopped me as i was to leave the store and asked for the receipt so i told him that since it is not busy he can go and get it himself as i am going back to get it. i was delayed for about 10 minutes explaining to the manager and the security which had torn clothes on which is less appetising that if they want the receipt they must go and get it themselves. i do not usually shop at spar as there is always shady characters hanging around the shop and now obviously i was treated like one of the people hanging around there. i will never set my foot there ever again.