Bad Service

I have a Fashion Express Account . My available credit is R510.00 short . I've sent emails to customer services since the 2nd of June to find out about my balance and have not received feedback to date . They have not responded to my emails or called me it's like the email address does not exit even though i get an auto response . On the 8th of June the balance was fine and today when i check it's gone down . Can someone call me or send me an email and explain why my available credit keeps on going up and down . I need an explanation because I'm now suspecting ***** .