Day light *******

I received funds from a customer last year in September.The client collected their order the following day.However later that day l could not transact on my account and when l called the bank to enquire ,they indicated to me that there were *****ulent activities on my account and they were investigating.I followed up with them for a while and they told me same story.They said they will contact me after their investigations were done.On Tuesday the 16 of April 2024, 7 months later,l received a letter from a Mzwakhe Twayi who said they were closing my account at the end of the month and they would put the funds into their suspense account as they were finalising an investigation.No case number nor investigation outcome has been given to me and here they are closing my account and placing funds that belong to me into their own account.On top of that they have been earning interest from those funds.What kind of banking ethics are these?Is this legal.Someone help me please.