DueSouth "Unprofessional Conduct"

I have been a DueSouth client for more than 10 years and never have I ever been so embarrassed by what they did. I always buy goods in store but it so happened that the store didn't have stock of the items I was looking for. The consultant informed me that I would be able to buy the items online as the online service is good. I tried the online shopping experience and found it very helpful. I ordered the items online and requested it to be delivered to the store closest to me. After collecting the items I was quite happy with the experience. Fast forward three weeks later. I wanted to purchase items in store and in full view of other patrons I was informed by the Manager that I had no credit available and that my account was blocked. This after I indicated to him that I had more that R17 000 on my account. I was so embarrassed to say the least as he could not inform me why my account was blocked. They referred me to customer "don't care"! I was informed that the reason my credit was suspended and my account blocked was because of my online purchase. According to them the transaction was marked as a suspicious transaction and did they revoke my credit and my account was blocked. The consultant casually said that they tried to reach me but to no avail. I confirmed my contact details with him and deny ever receiving any call and / or missed call. This did not save me any embarrassment. Had I known what they did, I wouldn't have looked like the Elephant in the room. No call, no sms, no email, no warning! How is this for Treating Customers Fairly?? After all these years supporting DueSouth I closed my account. Very unprofessional!