Pick n Pay - Bad service from pick n pay musgrave

I am visiting from Johannesburg, attending a birthday party and shopped online on the Mr D app on Friday 26th Aprol and the closest store was Pick n Pay Musgrave. The order was delivered and I realized the mistake that was made in ordering the combo deals. I needed to exchange the items and went to the store on the morning of the 27th April to do an exchange and this was refused by the management on duty at Pick n Pay Musgrave. I was told to request assistance from the app store. How pathetic is this service considering there was a need for the items at a birthday party and I couldn't do an exchange. I have called the Mr D customer complaints team yesterday 28th April.. I have not received feedback as yet.
I am shocked by the pathetic service rendered and still await an outcome.

Is this purely untrained staff or management that don't care about assisting a customer. Pick n Pay Musgrave you surely have given your brand the wrong exposure....I have never received this service ever ...Check my spend at Pick n Pay New Redruth ..excellent service always