Why can't I download BBM?

I have a sony xperia v when i first got my phone the person at mtn helped me add all the apps ( bbm and whatsapp) I cannot put my bbm back on because i lost the paper she wrote on. My phone went in for repairs and now i received it back but cannot remember my BB Id and password nor can i remember my email address i want to know is there any way of retrieving my details with my BB pin?

Sorry, you can't do much with your pin.
You'll need the email address atleast.

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