Haha... no... that doesn't earn me any cash back.
Looking for the best way to earn the most cash back, cause I have 2 astro account 

If you pay yourself at Astro website or over the counter, you won't earn 2% cashback (sorry for the error).

In order to earn 2% cash back under utilities/telco/mobile category, you need to sign up for Auto Pay/Auto Debit/SI.

You won't 5% cashback also as it is not classified as online transaction even though you pay at at Astro website.

Sorry for the confusion.

Not sure if anyone had experience on below.

Let say you purchase a item online RM300 using Cash Rebate CC, you should get 5%.
But few days later item out of stock so seller offer refund via CC or Account credit.

If i opt for refund via CC, will CIMB reverse my 5% rebate?