Call for an Investigation into the SNP's Missing £600,000, Who used it?

From around 2017 the SNP ran a campaign under the banner of Yes Scot.
The banner promised to Ring-Fence Donations that were to be used to finance a Second Referendum,
This money was raised by mostly ordinary people, many were not members of the SNP .
Indeed some donors dislike the SNP intensely.
The money was to be Ring-Fenced.
That means it is to be set aside for one sole purpose. Nothing Else
And as such should be separate and distinct from other finances or Bank Accounts .
In other words it should not be in the likes of a Current Account.
For the last approximately Two Years donar have been asking "Where is the Money?"
The people in control have avoided any answer , it appear to have gone missing,
The answers like "It's safe" "It's just misplace" and similar are not acceptable
From my limited understanding, of Corporate and Business Law , This money belong to the Donors given for a sole purpose and to fulfill that purpose
As those in charge of the SNP, Peter Murrell (husband to the First Minister) , Nicola Sturgeon(the FM) Ian McCann and Treasurer Colin Beattie
A concern is that the money has been used for other reasons other than , it's core usage
A serious inquiry into this,is required.