worst customer treatment EVER!!!!

I opened an account and was granted a credit limit. in my excitement i decided to go shopping. I collected my card from Cresta branch and made a few purchases and a payment. i then decided to buy myself something downstairs and when i went to pay, my card was blocked. i was moved from the cashier to the finance lady and told they have to call head office. i waited almost 30 min to have a consultant tell it is ***** and they must send my details to the ***** department. I was given no reason as to why they believed that and told to give them my ID and address details. i was producing my ID while making all the purchases . There was a queue forming and all i could hear was the word *****. The humiliation and embarrassment was so un-describable. people were staring at this point . I called the head office to have the issue resolved and my card unblocked only for someone to apologise for the bad behaviour and still leave my card blocked. I asked for a manager to call me back and was promised a call back after my case is escalated. No manager called back the next day until i called again only to discover that my card is still blocked. Imagine my horror and at this point, my payment reflects. All this time i am thinking that if i was not black, i would have been treated much better. at least someone would have had the decency to treat me as innocent. No one asked me if i can prove i am who i say i am and i had with me all my other cards and business cards etc. The treatment was not acceptable.