wrongfull accusation for shoplifting

Bought items for R749 and left the store. I then came back with my trolley and to buy additional items. I stood at the information counter and asked if I can pay there.When they said No i left because I was in a hurry. I was absent minded and and mistakenly left with Items i had entered to by worth R50. I was humiliated by the security gaurd in front of other customer and arrested. I admitted to leaving the store because i was very absent minded. However I was willing to pay for the item I hadnt paid for but was not allowed. I was then arrested. I am a young professional with high morals. Why would i shop for R700 then ***** these low value items.