falsely accused of shoplifting

I was accused of shoplifting at game store yesterday,someone bought pampers at clicks nd body lotion dawn on my behalf nd i ddnt take the slip from the i went to game store to buy some few items, i entered the shop and left my things by the parcel counter nd did my shopping nd took my things nd when i approached the security he asked for de slip for items i didn't buy at the store i explained to them and the manager but they didn't wanna hear my story i even asked for them to view the taping coz they have cameras but all they did they locked in up in a small dark room for 3 hours nd they called cops and i was not charged because i had a witness that lady working at the parcel counter so they let me go no apologies nothing,i wanna take further steps to this matter coz they treated me like I'm a nobody. I could not sleep yesterday thinking about this whole thing the embarrassment dat dark room with no chair no connection.what makes me angry they a statement without even asking for my input and my rights where violated i wanna sue them so bad,any one who knows where i can begin,also wanna write to the papers. They know nothing about customer service as for that manager,I'm disgusted