Nike.com refund

I ordered a pair of Nike Pegasus 37 on Nike.co.za, the item was one size too big and I returned the item back via Aramex. I received an email confirming my refund and it has been 15 working days and still, no payment was made into my bank account. Their best response was it will take 4 working days...well it has been 15 days...and claimed that it usually takes 2 payment cycles before the money reflects into my bank account...what does that mean?