Security Tag Mishap

On Sunday the 26th of June, I went to buy clothes at Ackerman's Kempton Square. The queue was extremely long and there were only 3 cashiers working, I could not understand why that was the case as it was month end and of course a lot of people were doing their shopping. I bought clothes for my kids and when I made two payment at the till as I was done, we experience load shedding, we were immediately told to leave the shop and therefore I left abruptly, I made 2 separate payments for the clothes one payment with my Ackerman's account card and the second with my bank card. When we left the shop I did not check to see that I have both receipts for the purchases made. When I got home and checked the items I realized that the winter tights that I bought for my baby daughter had the black security tag on them, now I do not have the receipt for the purchase and I am worried that if I go back to the shop to tell them about this I will be looked at a s a *****, I am extremely annoyed as I feel like this was the responsibility of the cashier to check and ensure that all security tags had been removed successfully. I feel like I wasted my money as I do not know how to go about handling this situation, I do not want to find myself in trouble with the law over such an issue. I cannot believe that I have been placed in this kind of situation and I feel helpless.