Cant call i cant make an outgoing call when in 3G mode but it can easily call when in 2G mode.I can easily received incoming and outgoing text..I can easily received a call..the problem is i can't make an outgoing call...

They are blocked by the carrier. Call your service provider

hypersim works only in 2g mode for outgoing and incoming calls no data

trt this one
Goto Messages - Email - Settings - New Account
Give a name for the account (Yahoo)
Settings
Connect using - give your gprs connection name
Email address - your email address
Connection type - POP3
Incoming server - pop.mail.yahoo.com
username - your email username
password - your email password
outgoing server - smtp.mail.yahoo.com

Now goto advanced settings

Set the check interval
Encryption - TLS/SSL
Incoming port - 995
Outgoing port - 465

Did you change phones? Sim cards? I am assuming you have the same phone, and they switched out the sim card (or maybe not?) when you changed plans.

Also, all 4G phones are also 3G and 2G phones, and they simply pick the best available. So if you lose 4G coverage, it will simply switch to the wider 3g network and when you're really remote, drop to 2G. This effects data speed primarily, there isn't any qualitative difference between them for voice and text.

It sounds like you might have something screwy with your sim card when the plan changed happened, I would call T-Mobile or visit a store and ask for a new sim card and be vocal about the poor reception after the plan change. Changing plans shouldn't normally effect reception, only changing phones/networks.

I myself experienced reception issues like yours, and the problem was a bad simcard. I'm sorry for the vague answers, but I think your best bet is to go to a T-Mobile store. They should replace the sim card free of charge.

Call your carrier and see if they have a lock on this. Some carriers do that because there is a fee for both incoming and outgoing messeges.

i cannot send text messages on my Nokia n97c. also the rear speaker is very quiet and is hard to hear when making a call. i am only useing 1 sim in the phone, and the network is at&t.

sync ur iphone with pc....it will work

It needs to say "GPRS" or "EDGE" in the top right hand corner in captial letters. If there is lower case letters, this indicates the phone is having an issue with the data connection.

Have you been able to send/receive email whilst in the country you are in now?

Most obvious things first, remove the battery, then re-insert and reboot. This will reboot the phone and create a new connection to the Blackberry server. Let me know how that goes.

This problem is with the phone and not the network. Takie your complaints to APple and have them fix the antenna for your device.