Poor service

I was sent money to my cellphone number a few weeks ago, my number is linked to an old account which is closed. I even received an sms from capitec confirming the funds. I obviously went to the branch in Eldorado Park and the consultant who assisted me couldn't find any record of me with my ID. He then advised me to open a new account so the funds can be available for me. I have been waiting for more than 3 weeks now still with no luck. How is it possible for such a successful institution not be able to assist with me getting less than R1000???