Horrible customer service

My fiance and i were promised free covers for our LG G3 phones which we had purchased about 3 months ago. After returning to the store in Cresta on several occasions to pick up the covers because we were advised to return on specific days when the LG rep Thulani would be in store athend even several calls to the store, we had not gotten anywhere in resolving the matter. I popped into the store yesterday and resolved to buy the flip open cover instead and was advised by the LG rep Chantal thAt she only has one cover left and she wud drop it off for me to collect today and I wud not have to pay cos the cover is free to LG supporters. I advised store staff to call me as I had wasted a lot of time visiting the mall to collect this cover in the past and it was not available. They asssured me this wud not be the case this time around. Today i returned to find no cover available once again! ****** staff did not even bother taking my number down once again to tell me when the ****** cover wud be available. This is absolutely unnaceptable service in this day and age! Does one need to make a scene and throw a tantrum in store to get acceptable service?