Claim for repayment of R3000, deposited on 26 May 1999

My mother opened an investment account on the 26 May 1999, and account number which she was given was, ********** 77. No correspondence was given since she opened the account nor the date of maturity. After some few years, she went back to the bank in Stutterheim, where she opened the account and the consultant, named Maureen told her to forget the money she will never get it back. 11 August 2015, i took it upon myself to make a follow up, bank in Stutterheim kept on making promises, up until i received an email from NA Ngubeni, who clearly stated that, the bank refutes the claim and denies liability. Deposit slips are still available, how can such a big Financial Institution ***** from the poor old lady, who is currently surviving on handouts from her children in such a cheap manner?