Has anyone used an add-on more than once in a billing cycle yet?

for example:
while on the Free Plan adding the $5- 200meg add-on twice to end up with
500 min/text + 100 meg + (200 meg @ $5) + (200 meg @ $5)

= 500 min/text + 500 meg for a total of $10

This way we can retain the original Free offer and add as needed.

I've only done it one-time without problem. Have not tried a second time, or multiple times within a cycle.

It'd be nice if they could automate it...I'd like to do your exact sample scenario each month since the coupons cover it.