I bought the 899 baht, 5GB "unlimited" data plan. I just ran out of the high speed 3G. Is there a way to add additional high speed 3G to this? I tried to purchase the same plan again, but since it's not expired it won't let me do it. There's also a 10GB plan for 1,699 baht. If I purchase that plan will the 899 baht apply to the cost?

I just saw in another post that you can add an additiona1GB for 150 baht if you dial *900*8903#. I just tried that and it says this "ขออภัยค่ะ คุณไม่สามารถสมัครแพ็คเกจนี้ได้ค่ะ" which means that I can't sign up for this package. I have the 899 baht 5GB plan and it's not expired, so why can't I buy the extra data?

Go to the following website on your True H plan phone... Look at the topping section with the limited tab...

http://hlife.truecorp.co.th

If Prepaid, you can simply cancel the plan and then re-apply. Often there is a short code for this. For instance, if you apply for a 999 baht 7GB package by sending an SMS containing V999 to number 9789, you should be able to cancel it by sending CV999 to number 9789. Then re-apply by sending an SMS containing V999 to number 9789.

I have no idea if these codes still work. Perhaps buy a separate prepaid SIM and try it out.

Thank you guys for the info. I ended up just buying the 899 3G package again trough that website. I have a new problem now. I just got a text saying the old 350 baht 3G package is going to automatically renew tomorrow. Obviously I don't need this package and don't want it to renew, but I have no idea how to cancel this. Does anyone know how to stop this old package from auto-renewing?