Renouncing of Permanent Residency

[Monet44]

I applied to renounce my permanent residency as I wish to apply for an eTA in order to transit through vancouver airport to catch an international flight - I was not aware I was even still considered a permanent resident - but apparently I was - anyway I sent in the application online and waited 72 hours that ended up being five days due to weekends and holidays - and got another message that they wanted a letter of explanation - (?) so I did that saying that i had been absent from canada and was therefore in violation of the residency obligations (something else I did not know) - and now there is a message saying they are reviewing my file to see if I am eligible - seriously - for what reason would I not be eligible to renounce my permanent residency ??