Poor customer service

Went to the cell c walk in store in Clearwater mall. A lady named Ayanda was rude from the word go. I needed assistance with the number I blacklisted on Monday via customer care line. I even showed her that the number is calling me on whatsapp call and normal line. She was very rude about it even if she didn't know the query. She just showed she doesn't care. I was very upset and didn't know what to do. She gave me attitude and told me I should call customer call because of the way I was talking. I asked her she would be upset too if u did a sim swop because your phone was ****** and someone is able to use your number. Her manager was sitting just next to her and didn't even say a word. That tells me that they use to been rude to client. It's like i walked in her mother's house for her to rude to me. Please provide customer service training to thses people no matter how upset the client is you keep claim and try to assist if you not sure ask for help. But hy cell c has *** service I am so disappointed.