Xfinity Mobile billing

So after a long fought battle with Xfinity Mobile, corporate resolution actually resolved the issues with me. However, they use some fuzzy math in their approach to my new bill. 
I was downgraded to what was “Unlimited” at $30 per line. My bill now shows $70 for two lines with a “two product discount” of $10. When I had “Premium Unlimited” it was $80 for 2 lines. The bill never showed $90 with a $10 discount. Why can’t there ever be some sort of transparency in the process? I’m getting my mobile for $60, but in a way that was not presented to me in the final version with the resolution team.