Freezing my son's account just because his inheritance was paid into it

My son inherited monies from my mom's Late Estate. When he turned 18, the estate advised me to open a bank account for him. Which we did online. A few days later ,the payment was made. We only knew about the payment when we went to the branch so that he verify himself (fingerprints ) and stuff to get his card, then we were told his account was frozen due to ***** because it was a large amount paid into his account from a Late Estate. So I said yes ,my mom passed away, that is his inheritance . So, he is in a total panic because he knows ***** isn't good but he isn't in the wrong either. So, Standard Bank tells him today an email was sent to Nedbanks communication channel. This was days ago. I contact the Estate Lawyer and he is like where did they send it? Nedbank is huge and has various departments, they can email him directly. Which to me makes total sense. Why send a confirmation email to most probably a general email address for a huge company when I have all the paperwork and can also provide the email address and contact number for the people who actually made the payment. I would like this resolved today and that my son can have peace. They are giving this poor boy the run around .