Amazing! That's exactly what they want you to do...ditch your BB10 device for an iPhone! They'll probably remove this post...but here goes. Surf out to CrackBerry.com and search for:
OS 10.3.1.2726 Live Links
When you've found that thread, the first page of it has the files you need. About six pages in, there's a step by step process of how to update your phone including how to thoroughly back it up.
I'm on Verizon with a BlackBerry Z10 currently running version 10.3.1.2744. I upgraded to 10.3.1.2726 and then went to 10.3.1.2744. It's much better than 10.2.
I was afraid to try this at first, but decided to go for it because of the frustration of waiting for something that I saw other people were saying was great. I've had an iPhone before. It's a fine product. I prefer BB10 however. That's what gave me the courage to pull the trigger and do this. My Z10 is like a brand new phone now.
In your post, you say you have a Z30. That's a better BB10 phone than my Z10! What a shame that you're going to ditch it because Verizon won't release the OS update. Oh well...I guess Verizon wins and some salesman gets a commission.