Amelia Arnica

I rented from Mattz Braxton a month of rent. The sign said if I paid a month it would be 8000L instead of 2100L a week. When I went to buy I was charged 8400L. I contacted him and got no response (as usual) but his manager responded and she said yes I would be refunded the 400L extra... I have tried now for over a week and tonight I was told NO REFUND. I have a copy of the sign that was on the land when I rented it and a copy of the NC of her and my and my husbands conversation assuring us to get the refund. Can someone help me I am not sure where to go and I know it is only 400L but still that's a bit of change. Thank you!