Need help to set up multiline/autopay discounts properly

Yesterday (7/11) I converted 5 postpaid lines on my account over to prepaid at the local ATT store. The rep activated and charged each line for the first month (which I think he wasn't supposed to considering he knew that I wanted to utilize the multi-line discounts). I was charged $50/$50/$50/$35/$30 ($215). They all have the same billing end date (8/9). I really want to take advantage of the multi-line discount but it seems like I would be paying again when I invite the lines. I don't plan on changing any line's plan - just want to merge them together.

• The FAQ makes it sound like I (line #1) would receive pro-rated credit on the rest of the lines (lines #2-5). When would I receive them?
• When I pay to merge each line, am I paying the full price of the line or the discounted multi-line price?
• I want to take advantage of the autopay discount as well. Since I would have to pay upfront to bring in a line, wouldn't that mean the autopay discount wouldn't kick in until the following month?
• If I need to do everything on 8/9 (inviting, paying, etc.) - it would apply towards 8/10 to 9/9, not 8/9 to 8/9 right?

My end result is getting everything down to $40/$30/$30/$10/$5 (totaling $115) after all discounts. I just want to know the best way to go about it. Please help.