We have implemented a blacklist on SAInPay division for the following 3 BINS, for refunds only 
These BINS cause format errors due SMS transactions being sent to Nedbank as DMS transaction.
What do we see?
The transaction returns a "successful" result, however the transaction does not reach the issuer/card.
How do merchants then refund there cards/BINS?
A manual refund needs to be processed by the merchant e.g .EFT
What is being done to resolve this?
Nedbank, Tymebank + other and PASA are trying to resolve.