Breach of contract/ SOLD laybye goods already paid

I visited the store and took a bicycle for my son on lay bye on the 5th Dec 2015, I confirmed with Daniel and he even advised me that it should be for Christmas present which I confirmed I will fetch and pay balance before 25th Dec. I also confirmed that to show how interested I was, I would pay halve which was R600 not min as per lay bye policy. On the 24th When I went to collect the bike it was SOLD and the store manager together with assistants brushed me off to say it was sold & my contract was terminated. To my astonishment & SHOCK, I was told to step aside & not disturb business which he casually smiles and asks me to wait for my money without closing contract because it was already CLOSED without my Knowledge. The manager of the store still goes onto to TELL ME that I was apparently causing a ruckus when I initially bought the bike. Why make up stories to make it seem like it was my fault for being your customer ??? and have my goods sold because of some absent manager can tell me what happened on the sale & in actual fact NOT THERE, while the sale agent was hiding behind his manager's skirt. My problem was the attitude, humiliation caused by MANAGER & BREACH OF MY CONTRACT.