I have setup 800 scheduled reports to email users a list of users in a certain security group to show who has access to the share they own. I have enabled 500 of these but then get an error

Cannot enable! Maximum Scheduler count for this license reached! Upgrade HDT/Scheduler Package!

We looked into this when purchasing and were told we could do the number of scheduled reports we required and cant see anything about the licencing about a limit. Has anyone else had this issue?