Inspired by this post, I made my super cheapskate attempts too and discover some interesting result
Tested using Digi Prepaid Campus plan (was RM0 before I reload), subscribing to RM28 4GB + unlimited call plan.

1. Reload RM10 (Touch'n'Go eWallet, random cashback promo -RM1.8, valid during 01 Aug - 31 Oct 2019)
2. Received SMS (reload another RM10 to get RM2)
3. Reload RM10 (Lazada, group play -RM2), get RM2 talktime credit
4. Received SMS (reload another RM10 to get RM3)
5. Suddenly received RM8 internet credit (not sure why)
6. Reload RM10 (Touch'n'Go eWallet, random cashback promo -RM1.4, valid during 01 Aug - 31 Oct 2019)*, get RM3 talktime credit too

At this stage, I have: RM30 base credit, RM5 talktime credit, RM8 internet credit

7. Digi deduct RM20 base credit + RM8 internet credit for RM28 plan

So I'm left with RM10 base credit, RM5 talktime credit
So I wondered can the talktime credit be used for AppStore purchase...?

8. App purchase in Apple AppStore (RM7.9), deduct RM5 talktime credit + RM2.9 base credit

So, in the end, left RM6.61 base credit (not sure why? maybe SST charge?).
Spent: RM30, cash back RM3.2 and lazada discount RM2 = RM24.8
Get: RM28 plan, RM7.9 app, RM6.61 leftover credit = RM42.51

So...
- * 6., somehow Touch'n'Go eWallet keep reject and refund my prepaid reload for 2nd time, I waited > 6 hours then try again, then suddenly can again.
- Talk-time credit can be used for AppStore/iTunes purchase (not sure loophole or not)
- Not sure how I got the RM8 internet credit, didn't receive any SMS prior.



This post has been edited by bergstein: Aug 12 2019, 12:30 AM

urgh I have this problem as well but mine was other game things...
Months ago I found out RM3 has been deducted, and I received no SMS/email on any transaction
After checking with them they said some Gameini things deducted that, but they only keep on advise me to unsubscribe any thing/remove weird app/etc, but I'm super sure I do not install any malicious app.
Until today it still randomly deduct RM3
So end up I just try to keep my account below RM3 until the date I need to subscribe internet plan

For BOS RM28 unlimited call prepaid, how to check the rollover data in their app?

Of course not 😓

well the statement of 'free data' leaking is very hilarious
but if you say digi leak data regardless of paid/free data then it's more logical 😁
internet is always leaky