Unfortunately, you will find the same treatment no matter which insurer you use, not just Medipac. I had a similar experience a few years back, different medical problem but similar response from my insurer. Like you, I felt this was unfair so I wrote to the Canadian Life and Health Insurance OmbudService. Here is the response I received from them:
Without seeing the involved policy I cannot with absolute certainty advise you on the insurer's contractual obligations. I can however advise that travel health insurance typically provides benefits for medical emergencies that occur while an insured is outside Canada. Once such an emergency is over so to speak, no further benefits are paid in connection with any subsequent emergencies arising from the condition with prompted the first emergency. If your policy contains a provision along these lines, then the insurer is right in advising you that it will not cover any further emergencies from your xxxxxxxx condition. The fact the this condition was not present prior to the effective date of the policy doesn't matter. You can always ask the insurer to quote the specific policy clauses they are relying on in this case.
Even though this is not the answer you would have wished for, I hope you find this information helpful.
Mary Boles
Associate General Manager,
Canadian Life and Health Insurance OmbudService Insurance Ombudsman