Extremely Poor Customer Service by Sunward Park Nedbank branch

I am battling to get my case finalized due to very poor customer service between MFC and Sunward Park Nedbank branch, I asked for refund due to being debited even though manual pay was made directly at Sunward Park Nedbank branch atm, MFC wants a deposit slip even though manual payment is reflecting and I told them I have misplaced deposit slips, that asked I I go to the branch to request proof, the branch manager told me she can't help me with deposit slip and that they will issue it once MFC request it from them, MFC says they can't request it from the branch I must do it myself, I'm now stuck not knowing what to do because either MFC and Sunward Park Nedbank branch are failing to deliver good quality customer service, if this issue is not resolved by 8th February, I'll involve my lawyers