Smartphone Service Plans

Ok, so I had a 30 day package with True Move H for 3g to use with my aircard as previously mentioned. I used up my allowed fair usage (3g)... so now I am trying to purchase a new plan so that I can get off of the bare minimum reduced internet speed it allows for. But this does not appear possible.

When I enter in the code of the package I want to order, the SMS reply in Thai says that I already have unlimited internet. But I just want to start over so that my internet speed goes back up again. Does anyone have any experience with this?

Do I seriously have to wait until the end of the 30 days and cannot buy a new package right now?

I believe you have to cancel any current packages before you can subscribe to a new/different one. Maybe call *9000, or *900? They used to publish the cancellation codes but I cannot find them anymore. The subscription codes are here: http://www.truemove-h.com/en//prepay/prepay-topping.aspx

So for the 899 plan, enter *900*46# SEND/CALL (press the button you press to make a phone call or send an SMS)