Signal or Condtional Boundary Event of sub process

The stop credit system

  1. Check Stop Credit
  2. If credits up to date, continue with approval
  3. If not, Check if they have special arrangements (Delayed, or quarterly payments etc), Continue to approval. If they do not have special arrangements, Cancel order

Based on the above information I have modeled a sub process. What is confusing me is, if they do have any special arrangements would it be a conditional or signal boundary event.

Secondly - I have put ‘Apply Stop Credit’ as a call activity. Is that true or would a call activity be the one in the image or further in the process, where lets say a customer has delayed payment so the finance officer will have to 'Apply Stop Credit", or would it be both?

Appreciate the help.