Is the CSV file comma or tab delimited? We use comma delimited. Make sure that the first line is something similar to:
Date,Reference,Description,Amount
An example of 3 records including the header is below, try to import that into a test business (create a test business and enable bank and cash accounts, receipts and payments in Customize):
Date,Reference,Description,Amount
01/04/2022,0,ACCOUNT MAINTENANCE CHARGE,-5388.18
01/04/2022,0,VALUE ADDED TAX,-404.11
01/04/2022,0,TRANSFER BETWEEN CUSTOMERS Via USSD Bank Transfer
Note that you need to have separate lines for each transaction