Incompetence

I bought a dress from Zara. when I got home I noticed they didn't remove the security tag . I didn't keep the receipt because everything fitted correctly. On the 27th October I took the dress back to remove the tag I informed the security and explained I didn't have the receipt. He advised me to proceed that they will use my card to locate the purchase. I was then attended to by a supervisor by the name of Mbali. She then told me before she take out the tag she must check if the item is not missing from thier stock. I asked her if she was implying I stole the item she said not really but the sales person might have given it to you. my understanding is not only did I ***** the item I was in cohesion with one of thier staff members. I then showed her proof of payment on my phone of which she was not interested. Am really disappointed with the supervisor conduct Not only was I wronged i am also being accused of theft