Vodacom unable to assist with debit order change for a deceased account

Been emailing Vodacom since 10 April 2016 to change the debit order details on my late mother-in-law's Vodacom account. Had to re-send the email on 2 May 2016 as we have had no response. Just received an email from Alida Brown at Vodacom requesting to make contact with their legal department via phone as they are unable to process the request. Called Vodacom Legal only to be told that their systems are down & that I have to keep on calling until the systems are online again.....This is unbelievable, such poor service, yet they tried debited her account again & we are no liable for bank charges as well.