I was over charged

On the 31 October 2017 I payed R2000 on my account and balance was R2474.62 , on Wednesday 8th November I bought clothes worth 1379.70 at Edgars Cresta mall and again at Jet Cresta mall I bought clothes worth R532.95. On Thursday the 9th November I bought shoes worth R1299.85 at Fourways mall, my account balance was R5686.12 . On Sunday the 12th November I needed to buy clothes worth R1300 at Foresthill mall were I was told that I can't buy those clothes worth that amount saying I can only buy clothes of R700 as my account owe R6220.07 . Then On the 13th November Monday I went to fourways mall to inquire about my account's balance, I was told that as from Wednesday they had system problem. On Tuesday I went to Eastgate mall to inquire about my account's balance the lady that was helping me contacted their customer service whom I spoke to and they promised me that my problem will be resolved in 48hrs,and that they will contact me,on Thursday later I went to Foresthill and I found out that they didn't solve my problem, and the lady who was helping me contacted their customer service after 5minutes on the phone they hanged up the phone on her. As of today Edgars did not call me nor fix my account's balance. Edgars doesn't care about customer service, poor service.