FNB missing money from my investment account

Good day. I need someone to help me sort out my issue with fnb. On the 25th of June 2009 I invested R160 000 with fnb. Today I went to try withdraw my investment and I was told the funds were not in the account and that the account was closed yet I have never went to request for the funds till today? How is this possible please someone make it make sense how money that’s been in an investment account that I personally started 25 years ago is somehow dormant all of a sudden when I never not once requested the funds?