TMo already provides free TXT alerts for overages. In fact there is a
warning message at 45 min remaining.

punnu35@gmail.com wrote:
> Launched a website to protect you cell phone minutes to reach the
> maximum allowed minutes.
> www.stopoverage.com
> its a free tool and you get free email alerts.
>
> It supports verizon and ATT right now. Looking for t-mobile beta
> customers. Please email us at support@stopoverage.com if you are
> interested
>
> Thanks