The reseller from his CCP tries to place an order on the service plan which is delegated to him, it fails with an error:
You can not use Plan #ID. Permission denied.
The issue is caused by the bug with id #PBA-63285 ("Unable to place order by reseller on plan delegated to him from CCP").
As a workaround you may place an order for the reseller from the providers control panel. For a permanent resolution install hotfix #125299 or update to BA 6.0.4.