Depending on your data you have to be careful with your joins and your select statement. This type of thing is usually easier to get with views or stored procedures. If you cannot do that one way is to pull all of your debtor accounts into the report and flag items that DO have results that fall into your time frame and then remove them using a group summary selection.Based on your overall needs you have to tweak this but here is a basic process. Also this assumes that each debtor record has at least one record transaction for it. If not you will run into some NULL issues that this process will omit it as a record.
Group on the debtor account field.
Create a formula to count records that fall int he time frame. Assuming you want to use user defined parameters it would look something like:
if {table.datefield} in {?parameter start date} to {?parameter end date} then 1 else 0
Use the summary function to create a SUM of this formula field at the debtor account group level.
from here you now have determined that any debtor account with a SUM of 0 had no transactions (this is where you will have issues if the debtor account has no transactions at all.instead of a 0 it will be null as a summary)
You can now do a summary selection criteria. CLick on the summary field and then click on the record selection.
You should be able to add in the group selection criteria of:
Make sure in the select expert you have the Group Selction option toggled on. This cannot go in the Record selection portion.