Disgusted with Duscovery Bank

My sons phone was ****** and ******* managed to access Discovery bank app and purchased airtime for R30000. 00.Discovery bank refuses to reverse yet vodacom says they can do it from their side. My young son is traumatized as he doesnt earn much as an intern, this was his savings and credit money which belongs to discovery bank, he was saving towards a computer to use for work and gaming and greedy Discovery bank will not reverse this money but rather sends him accounts notifications for him to pay them back. I am disgusted and very disappointed in service given to my son by large rich company.