handed over to collection agency

So after lodging a complaint on Hello Peter, I was contacted by a Vodacom representative and advised a credit note would be passed. This was done but when I phoned Vodacom for the status of the account I'm told the account is with a debt collection agency. I've not been contacted by anybody and cant seem to get information on the status of this account. This company is so, so tiring to deal with, nobody want to assist you until you complain on social media!!!