Very bad customer service

Third time in 3months i have had to leave a truworths store because they did not have enough money to refund my purchase branches include Tygervalley....N1 City.....Parow. yesterday i checked online on a dress which they said has 1 at V&A waterfront. When i got there they had the dress on a mannequin and refused to take ot off "they are not allowed to" what the hell!!!! Im the customer what happened to customer service inthis country and this is waterfront!!!!after my very bad attitude and threats the manager eventually conceded. I expect so much more from a company like truworths. So disappointed. Wen i bought the dress they didnt say take the dress cone back when you have all the money so why can they not refund me....