Manager rude & unwilling to help

I went to Vodacom this morning with my mom, to try and get a paid app downloaded onto her the tablet she had bought from Vodacom. We had tried the previous evening to download the app (which costs R499) but it timed out halfway through, and we weren't sure why. We didn't want to accidentally pay twice, so we wanted some advice. The manager of this little shop (in the shopping centre opposite the front entrance to Westville Girls High School) told us upfront that he would charge R150 for any help he gave us. We told him it would just take a minute or two, and that we were unsure how to use the tablet she had bought from Vodacom. He said since she had not bought the tablet from his store, he would not help us. I asked him for his business card and name, and for the name of his manager so I could make a complaint. He said he was the manager, and refused to give me a business card. I thought his behaviour and attitude were unacceptable, and this will put me off ever going into his shop again.