1 month payment suspiciously went missing

My husband and I have been with Lewis (Claremont - Cape Town) since Dec 2014. Recently I discovered that one month payment mysteriously went missing and when I enquired about this, I was told that one of the sales people (Mrs. Smith) at Lewis refunded my money (1 month payment in cash)and she signed for it, however I have never ever received any refunds and according to their system I am still one month in arrears. They even came to fetch my lounge suite when I paid a few days late, because there system shows that I am already in arrears. I am 5 months pregnant and I've been to the store numerous times to sought this out but to no avail. I keep being told to come back. Is there anyone that can assist me in getting this soughted?<br> <br> Yours truly,<br> Jillian Swarts<br> ***