Ackerman's Cavendish doesn't care about its customers

I'm sooo frustrated and angry at the same time with the attitude I got from Ackerman's Cavendish, I went there during my lunch break to exchange the item I bought the previous day bt after waiting for a long time in a que when I finally got to the cashier I had to wait for someone to come and authorize and she made sure she took her time and whn she finally got there I was already panicking because I was late but I was calm until she nagged me about buying airtime with my change wheras I made it chear that I don't want to purchase airtime and I'm late so she must just give me my change until she did gv my change and slip,in that whole process I forgot to take the Item I came to buy,because I had another shopping bag from another shop I didn't notice anything until I got at work and was already late so I went there the following day 1stly they were reluctant to help m because they say It couldn't have happened because I have my slip 2ndly when they finally went to check the footage they come back after 30mins and said there was nothing on the counter so I asked them does it show me taking the Item from the cashier and how and when did I do that when we were still waiting for someone to come and authorize they couldn't answer me. All I want is my money or the Item I bought, I lose my money just because of their bad customer service and what irritate m the most is the manager's attitude she couldn't care any less. All I need is my stuff