Get a refund in Poland for medical expenses abroad

Hello,
I'm resident in Poland and pay ZUS here.
Last month, I went to Belgium and got ill. I went to a doctor and had to buy antibiotics at a pharmacy.
I've got the bill from the doctor and from the pharmacy.
Can I get a refund (at least partial) from ZUS or NFZ? How?

Thanks for your input

Did you consider walking into the nearest ZUS or NFZ office and ask?

Actually, not yet, because my wife says I can't get a refund because I went to a private practitioner, so I wanted to hear from other people first, before going to an office. Will go tomorrow morning, I've got time.

Maybe this helps a bit:
europa.eu/youreurope/citizens/health/unplanned-healthcare/payments-reimbursements/index_en.htm#shortcut-2
and a Polish source:
poradnikzdrowie.pl/sprawdz-sie/niezbednik-pacjenta/kiedy-nfz-zwraca-koszty-leczenia-za-granica-w-krajach-eu-aa-ACox-iq93-4hx5.html

Just for the sake of completing the discussion (better late than never) to help others who could have a similar question : I went to the NFZ office, filled up a form and attached the bills from the doctor and the pharmacy. Shortly afterwards, I received the refund on my bank account (approx. 70% refund).