Home loan surplus after settlement unpaid

My partner recently sold a property, bonded by Standard Bank, of which she was 50% owner. The other 50% was owned by a deceased estate. The bond cancellation sum was paid on 10 February and a surplus of R88,606.99 remained on the account. On 10 February my partner went to a brand and supp**** her bank details, as she was due 50% of the surplus (R44,303.50) but was advised that the bank would not pay until they received certain documents from the executor of the deceased estate. The executor subsequently supp**** these documents but after a month of waiting, with no news or payment from Standard Bank, she visited a branch. She was advised that the full surplus was erroneously paid in its entirety into the executor's bank account. My partner was supposed to be paid 50% of the surplus and the balance to the executor. Standard Bank have made a huge mistake here and need to rectify this immediately. She was the joint bond holder so Standard Bank needed authorisation from her, which she did not give. We will report the matter to the ombudsman for Banking Services and the FAIS and if the expected sum is not paid to my partner we will pursue legal action against Standard Bank.