Refund

Checkers 60 Tambotie mall, I ordered 24 products and only 21 were delivered and they took the full amount when I try to send a query via the app the app requires me to make a call meaning I must have sufficient airtime. Did I not wait for over 3 mind for someone to answer my call. I just need my query resolved, can I have my money back please. You have no right charginge the full amount but sending less items than what I ordered. This is happening for the 2nd time now!!!!