I hope they can, but I will update with outcome
@celidhkk One more thing to try. Go into the APN menu. Turn off Wi-Fi and Bluetooth. Select the reset to default option from the APN menu and immediately put your phone in Airplane mode and hopefully this may afford you enough time to perform your APN modifications before that happens again and you lose access to edit them.
@celidhkk Edit: See above as I had the order wrong.
Read this thread it is the same issue and there is a possible solution for you at the end.
I believe the only option is using a current or used freedom or roam sim card to change and configure your APN. Do you have a friend with freedom? Sometimes they are nice and will let you borrow one at the retail outlet.....
@tblaing the Freedom Sims are $2.99 at Canadian Cell Supplies