No response leading to unfairness

I am very disappointed with istore! I went into their store (pmb) last Saturday to purchase a drone.. after asking the necessary questions and getting my details taken down.. I was assured that I would receive a call from an employee at the store to let me know if the drone I was looking to purchase could be sent over from another store.. I received no feedback or call from istore Pietermaritzburg! I tried calling the call centre as there is no direct line to the actual store. The call centre just places you on hold with a repeat message to either message them on a WhatsApp call or wait for assistance. It further adds that it has a high volume of callers. But this is always the case. I tried many times and I sent the WhatsApp messages as well. I also email the Pmb store manager to let them know of my order. I finally received a call from istore today (Friday) to let me know that they have received stock of the drone that I am looking to purchase. The unfair situation is that the drone was on sale all the days that I tried to purchase it. The sale has now ended and there is no reassurance from the store that I will be given the sale price as common curtesy. Please can istore South Africa be kind enough to reach out to me and give me the sale price that I clearly deserve. Thank you kindly.