Unprofessional

I bought material from Cashbuild Mthatha Callaway str a month ago, they had two deliveries the other one was successful n then 2nd not so good because not everything I ordered was delivered, tried to call them then they told me ,they will see to it,I had to buy those things else where because I needed those things urgently. So I called their head office because they were not picking up the phone,their manager called me and explained how their delivery works I understood ,then I asked for a refund because I already brought those things on a nearby hardware. He said I can send someone to collect the money then I asked my little sister to go. The service of the lady that assisted her was very bad she gave her a bad attitude and making remarks she even said that I took a loan for the material but I want refund. What I dont like is she had her facts all wrong because I didn't take out a loan she just assumed I did.Even if I took out the loan I don't see how is it any of her business because I was gonna pay the loan thats part of how they make money and how she gets her salary. And the person she was making the remarks to didn't buy any material I did. What about customer confidentiality, customer service,professionalism?