IDP IELTS — about the refund

I have booked IElTS exam through IDP and due to some personal reasons i have applied for cancelled exam, And they also approved for my refund, IDP customer care person tell to me that the amount will be credited with in 15th aug 2018 but till now my amount is not credited in my account.In below i have attached the proof also and then if i call for this problem they are not giving proper response .Kindly take this issues seriously and solve this problem

In this i can't upload my audio because it can support videos and photos, If you need i will send through email