VAT Number-Old customers

We have few customers who are under bad-debts. For these customers we dont have any contact information and currently they are under legal review. So, if we issue credit notes to these old bad debts customers, there will be no VAT number & the address will not be in line with National Address format. How should we handle this situation ? Do we issue credit note without VAT and if so, how the XML will be treated from ZATCA integration rules because it will not have any VAT number & incorrect national address format ?

As per VAT regulations, a credit or debit note is issued for an existing invoice in cases
such as Cancellation/Termination, Material change or alteration to nature of supply,
alteration in previously agreed consideration for supply, return of goods. Such credit
note or debit note shall include the information required by these Regulations to be
shown on the Tax Invoice.
A Credit or Debit note is either based on a Tax Invoice or a Simplified Tax Invoice and
is subject to the same issuing requirements as the type of invoice on which it is based.