I owe standard bank nothing.....

I had a cheque account with standard bank and later closed it around 2016 and deposited the outstanding balance to close it and I received numerous calls from standard bank saying I owed and needed to pay and I told them that I don't bank with them anymore and I asked for a statement that leads to the amount they said I owed and they never did and stopped calling and lately about 3 months now received calls from NDS attorneys on behalf of standard,I asked for a statement too so I can prove the I don't owe standard bank a cent until today haven't received a statement on emails.they decided to reopen the account not me that added to R2800 and something.The boring thing is also this NDS attorneys keep sending smses demanding the amount even though I asked them to ask the statement for me from standard bank but nothing had been done,now they stopped calling but kept smses coming through and it's so irritating