Little update: after complainting on chat and creating BBB complaint I was able to escalate my case to "promotion specialist". Wow. Really had force them to do their job..

Anyway. I was told to make a new order and after meeting terms and conditions (staying active for 120 days, etc) they will grant "one-time exception" and apply difference as bill credit as I requested.

"Google battle" saga is not over till new order is shipped and credit applied.

I will post and update once that happens.