Just a suggestion, but if you're able to, try to contact JPA only via e-mail and make sure that you keep all of that correspondence recorded. Point out to them that you do not wish them to contact you by telephone and, if you're still having problems after a reasonable period, tell them that you intend to keep all of your e-mails to form an audit trail for a possible formal complaint or legal action. That seems to focus their minds!
If things get really bad, try copying your e-mails to your chain of command so that they can be formally aware of your problems too.
Best of luck!