No Feedback regarding Dispute

I submitted a dispute relating to my mastercard on the 3rd April. I phoned the call centre at least once a week since and I'm told that the analysis will contact me within 48 hours. still waiting. I called again this morning and was kept holding for 19 minutes while the operator tried to find a team leader and still can give me no feedback. I am sitting with almost R700 out of pocket and it has been over a month and have heard nothing!! Disgusting service !!!!