*136*9*1# doesn't work anymore. try *100#.

same here, maxis cs asked to reset phone, restart phone and etc. still doesn't solve my problem since Friday.

Same issues here for both my principal line and supplementary lime. I can't check my data usage. It shows "your current mobile internet usage is not tracked. to subscribe to a mobile internet plan dial *100# > internet and settings."

I'm going to file an official complaint to Maxis and subsequently to MCMC and CFM if I have been charged for my data usage in my next bill.

Called 123 and they confirmed that I'm on Ivalue Simple Plan with data package for both lines. I did checked my unbilled amount and the amount is more than my normal usage. So I still doubt that they have charged me abnormally.

the ivalue simple plan is actually talk more RM28 + 1gb data at RM48, total=RM76. But you only pay RM50 per month to get the ivalue simple plan with iphone 5 purchase with 12 months contract.