Struggling to retrieve funds (Reversal Request)

In 2013 our company stopped banking with Standard Bank, The account was closed and we moved to another bank. We forgot to update the new account details with our music publishers, so for the past 5 years our publishers have been paying our music royalties into a closed account. I only discovered this late last year after going thru documents and realised there is some money we have not been getting infact it was triggered after one of our artist/s was enquiring about his separate invoice for a 6 episode TV soapie gig we got him in 2017. So I went to the publisher and notified them about this error, they said all payments were made over the past 5 years and payments have been going thru non of them were returned like they usually do with a closed account. I then went to Standard Bank to find out how come the money is not bouncing back to our publishers account since our Record label's account was closed in 2013? Standard Bank told me that they have since re-allocated our old account number to another business organization meaning that all the royalties meant to be paid to our label has been going to this new company that Standard Bank re-allocated our old account number to. I then asked, how do we fix this? Showing then all proof of payments from our publisher which were meant for us. Standard Bank said they need to get permission from the new company to deduct the money then pay it back to our publisher, they later said it looks like that particular account didn't have funds and there is nothing they can do. Meaning that business basically received our royalties for 5 years and spent it without questioning it. Standard Bank is not willing to resolve this issue at all and has since said we must open a court case in order to claim back our money, Now the court case Is just another task all together and it will cost money. Isnt there a way this can be resolved with going to courts.