account settled in cash but now being harassed

In 2011 I went into the autopage store at Cape Gate mall in Cape Town. It was 4:50pm and they had already started to shut down. Told the lady I had to make payment and she told me to come back. Told her the store closes at 5pm and I could not come again. She accepted my cash payment and have me a Manuel receipt. Four years later(present) I am being called and harassed for payment. When I told the consultant that payment was settled