Nedbank ***** department is not doing their job

I did a legitimate business by selling bitcoin and after 24 hours Nedbank debited the money from my bank I went to complain to know why and I was told by nedbank that the buyer had called his/her bank (standard) bank that he had mistakenly transfer the money in my account and they will carry out investigations that I need police affidavit and I should open a case which I did and in the process they suspended my account and then after two days they debited every cent I had in my account and then I called to know why well they told me that the same person reported to his/her bank that it was ***** which I told my bank (Nedbank) to do the investigation thoroughly and I even sent the ***** department the email and proofs of the transaction but my bank isn't do anything and I have a son for over a month now I don't have groceries, I don't have money to pay my rent, I told them that I don't have money to pay my son's school fee and feeding schemes but they show no remorse and instead they kept telling me what the standard bank complainant is saying without even verifying the proofs that I sent to them and again the same person de*****ed some other two or three persons with his/her account in two weeks after mine and I sent the proof to Nedbank but they just don't care about it. I'm so stranded and afraid what if my landlord ask me to leave his properties and my son get kick out of school and he doesn't even have food because I can't afford anything for a month now. I'm so not okay please I need help.