thrown out of shop after enquiring about special

went to southern spar in germiston south after I saw a special on their weekly pamphlets. it advertised 'ceres 200ml juices for R19.99' buy 5 and get 1 free' went in got my 6, 6 packs with the hopes to get the 6th free. before I even got to the counter a man who identified himself as tony was already on my case asking me which country am I from where have I seen juices so cheap while I was showing him the pamphlet another man who said he is mark told me I must get out of the shop next time I come to his shop I must bring a warrant.