HORRIBLE customer service from CLICKS call centre

As a loyal Clicks shopper I cannot believe the terrible assistance I received by call centre manager, Nazeem Reed when calling the Customer Service call centre because of an error/query on my Clicks Clubcard balance. Because I work right opposite a Clicks store I pop in at Clicks almost everyday. So, on one occasion I used my Clicks reward points for my purchase. A few days later I was in the store again and at the till point upon paying I asked the cashier why the total amount due by me was so little he said that I have rewards on my card which he used for the sale (and apologised that he didn't ask me first but just used the points) I then just paid the balance. Then a few days later again I was at another store and the cashier asked if I wanted to use my points, I was surprised and asked if he was sure there are still points on the card and he assured me there was and said he will just check again if it is available and after checking the sale went through. A few weeks later upon visiting Clicks again, I checked my points only to see that my balance was now in a negative. I called the call centre to query it and the service centre agent said that it could have been an error on their (Clicks) side but he would speak to a manager first. He came back and told me that the manager said there is nothing they can do about the situation. I asked to speak to the manager upon which I then spoke to Nazeem Reed. I explained to him and asked why I should be held accountable for Clicks' error. He was VERY rude and made me feel like a ***** when he said, there is nothing he can do because I TOOK THEIR MERCHANDISE SO NOW I NEED TO PAY BACK CLICKS' MONEY!! He did not even try to investigate the situation further. I am very disgusted by this service!!