Disgusted with Standard Bank

I receive monthly investment from a major insurance company paid into my bank account on the last day of the month. The Insurance company has reassured me that the transfer was done on the last day of the month but the money only reflected early evening on 3 April 2018. I have raised this issue with Standard Bank but the practice still continues. Whenever the last day of the month falls ove a weekend or a public holiday, the money only reflects the next working day if I'm lucky. My money was transferred on 31 March 2018 and only reflected this evening 03 April 2018. Due to this delay on the part of Standard Bank mine and my wife's accounts are in arrears and our credit score/rating is now affected. This is unacceptable and I shall take up the matter with the Banking Ombudsman as it's now become common practice for a bank that's supposed to be working for us.