Delay in migration costing clients

Good day, could you advise on why clients are liable for the additional fees incurred (e.g. withdrawals, pay to cell phone) due to Nedbank's delay in the migration of the Savvy Bundle to MiGoals Premium accounts through no fault of our own?

How do I go about getting refunded for the fees incurred due to Nedbanks delay in migration?

Complaints department and direct email to client services manager have not been helpful answering my question.