Sometimes payment methods do change however in order to hide these the options need to be added to the Meddbase system for them to be hidden. This is located: Start Page > Admin > Configuration > Accountancy > Hide Payment Types.
However, this section does require for the Payment Method code opposed to the name of the payment method. This information can be obtained from generating a report using the payments root table. The column required to provide this information is the Payment Method Code, including Payment Method Name allows for cross referencing which payment method has which code.
Using this information by entering 'cs' into the Hide payment types as below, will hide Cash as a payment method within Meddbase. Multiple codes can be entered and separated by a comma.