I want my sendimali reversed to my account

On the 23 December 2019 I transferred sendimali to 072157***x, the recipient sent her sister to withdrew the money only to be told the money is stuck on the above cellphone number and locked into a mobimoney account because the 48 hours has has passed. Nedbank did not reverse the money back into my account till today. I have been calling their call centre for months now and are still not getting my money back. I even spoke to Cherise on their call centre and other numerous agents from this bank with no assistance instead we are been taken from pillar to post with no assistance. I was given ref ***2 to call after a week, even went to the branch with the recipient and now the story has changed again.....How many times must I go to the bank to resolve this issue only to be told i cannot access my money...now they have changed ref to ***2.