Edgars account

I paid R700 for September 2020 inside Edgars Store at Jubilee Mall In Hammanskraal it was paid in cash. To my surprise the money went missing and the slip is fading with information that is not showing clearly and now the refuse to pay it back to my account because they said they can`t allocate the money and I must pay for arrears and the calls the made for harassing me .I was paying into three different cards number .Now I paid R2700 to my account no more calls from them but R700 is stilling missing and I can`t recover it no one is attending to my problem.