I have been using China Mobile unlimited data every time I went to HK for the last few years. Never had the problem you mentioned.
I always double-checked the unlimited data status before using data, via their SMS confirmation, and checked balance regularly. I would have been more careful after the 2nd top-up in your situation and verified the balance after using it, and called their customer service right away, or went to their store to sort it out.
If your balance was truly at ZERO, you wouldn't have been able to access data, because their system is set up so that whenever you start a data session, $5 is deducted from the account, and subsequently returned to the account when the session ends. Zero balance = no data access, even if you have purchased an unlimited plan.
Minimum top-up for Chinamobile is a lot less than HKD100 through other venues:
- China Mobile Store $10
- online $50 (including foreign credit cards)
- vouchers from convenience or phone stores $30, $50, $100, $200 or $300
- 7-11 $100
3HK has the fastest prepaid data speed. May or may not be the best prepaid service for you.
Billing error can occur with any provider.
Last edited by beep88; Jul 16, 2011 at 2:22 pm