Complaint to Markham

I was at Markham to buy my Christmas clothes,they had a special, where you buy for R600 and you receive free flip flops,I bought staff for R4000 that day after we had finished everything, as we were going out that's when a staff member calls and says thank you for buying here ,as a manager I am giving you free pair of flip flops,why didn't they say as we wetebin the store before paying ?******,staff is taking those pairs of flip flops at our expense,this is not good at all,manager himself at vaal mall is involved..this needs to be put into consideration honestly, I actually want those flops which they take on my account ,I have all banks I would have paid separate if that was the case so the that my family can enjoy the benefits..totally unfair, they do know my face,I would like you to assist me I will take my ID with for reference.. I have the proof.cashiers were very rude when we asked them the next day..I need my shoes which whosoever staff member benefited on my account took..