hero did not unlock

The same here. I've completed both quests (25 games each): for new plant-hero and zombie-hero and still have only 2 plant heroes and 2 zombie heroes.

Another topic for similar issue: http://answers.ea.com/t5/Technical-Issues/Final-hero-selection-Missing-after-restart-app/td-p/5667195

Yup, support is a joke for this issue as well.

3 weeks after reporting my issue, and reportedly having my case escalated to a specialist, I finally get a 'resolution': 100 gems credited to my account and a statement that there will be no additional compensation.

I guess that's just par for the course with EA Products...

they want me to beat the next level, but there is no level system in this game.. and how is playing 25 games even related to levels?

I was told that as well.   As far as I can tell they do that to blow you off as fast as possible and close the support case.   It did not work to fix my issue.

The 3rd party they have handing support must have compensation metrics based on closing tickets, and not on actually resolving issues.

same problem as you

same to me

I got the message... to beat a level and as for the issues they'll give me 100 gems...but after beating a level i still havent gotten a chance to pick a hero...i have finished the zombie hero quest and plant quest too! ☹️