my missing grocery items not replaced by the store

So Pick 'n Pay Groblersdal Mall has hired ******* from management to cashiers to security guards at the door. So after work i went to do my grocery shopping at the store and the cashier packaged my stuff and i left to my car. When i was about to drive off something just said check your grocery and boom my snacks are not there. I had to go back and when i got to the security my snacks aren't there, the cashier left the till where i paid, then i had to look for the manager and when i lodged my query that my snacks are missing with the 'supervisor'. He said that they can't operate the cameras and as he was saying that all of a sudden we realise the snacks are at the security table already opened. All of them did not even try to apologise or look for me after they realised that they have not packaged all of my grocery because the cashiers at the store are the ones responsible for carefully packaging customers groceries as a courtesy. So tomorrow i will be seeking legal advise whether i can open a case of theft against the stores. The cameras must tell us what went down. Honestly, i feel ****** because those snacks i have paid for with my hard earned money. I have kept the receipt, i want to be compensated for the time wasted going back to the store and the emotional stress they have put me through regarding this event. How many groceries go missing unrealised? They have really broken the trust i had for the store. Oh and as for the attitude they portrait it was uncalled for. They have shown lack of sympathy. I mean no one even tried to apologise. I feel they don't care for their customers but their sales. I mean, I had to come home late going back to the store to sort this issue. What if i only saw that my items are missing when i got home, even worse what if i was going too far from Groblersdal?