My Credit is Missing

I opened up an American Swiss Account earlier this year, surprised about the Amount I got in Credit when I received my Card, so I decided to spend just a little (About R600) just to keep the Account running, and saving the rest for a special day in the Future, and the special day is coming closer and closer so that's why I am here, now. On my statement, as at 12 Apr 2017 I had R7893,00 to spend with a Balance of R606,93 which means I can still spend R7893,00, this is the amount I did not want to use, to save for a special day. I neglected looking at my statements, to see what was going on, how much my Credit was and so on, until recently I went to American Swiss at Brits Mall to buy a Ring, a Ring my Girlfriend really likes, which I wanted to use to propose to her but unfortunately my Credit was missing from my Account, with the response that was given to me, from the Head Office "It's an error". Now, to fix that error, I was asked to fill in a Credit Form, to increase my limit, that keeps on being declined, with unknown reasons like I don't Qualify, NCR declined me and so on, but where is my original Credit, that was on my Original Form that was signed by me in the Store? I lost R7893,00 in Credit from American Swiss that was mine, in my Contract with them so I see that as a Breach in Contract, and I suggest it should be resolved soon because I will be taking it further if nothing is going to be done. I can understand being declined for a Credit Increase, but I want my Credit back that was taken from me, and I recommend it should be dealt with soon or else I will be pressing serious charges against your Company.

Good Day.