wifi hotspot disabled...how to restart it without paying $15 a month fee

I've been very happily using my wifi hotspot to access the internet on my computer at work on my nexus one for quite some time. Yesterday, Tmo blocked my screen with an upsell ad requesting that I enroll in their mobile hotspot service for $15 a month. I called, thinking that my unlimited android plan with free hotspot would permit me to use the tethering\hotspot capability of my phone without charge. I was told that the hotspot functionality was for "official TMO. hotspots, like in the airport" and not for using my phone to hook up my laptop to the net. They said that I waqs NEVER permitted to use this but their technology only recently found a way to block this.

I'm trying out an app called SVTP hotspot lite that seems to work....although only on firefox not chrome.
I may buy it, but want to research my other choices.

What options do I have?
thanks in advance

thanks

Which data plan do you have?  There was a promo data plan that had the Smartphone Mobile HotSpot for free that ran earlier in the year(started toward the end of January), and that one should not have any problems acting as a wifi hotspot.  My data plan is Unlimited - Premium with Smartphone Mobile HotSpot Service(the promo plan, jumped on it when it was being offered for the same price as the regular 5GB data plan.

The user agent switcher in Firefox or Chrome which basically makes your computer browser appear to be a mobile device should continue to work after you receive the upsell message.

Non-browser software on your pc should still access the internet fine.  (Such as music streaming)

As Inuyasha said, the current 5GB plan has hotspot included. 

What data plan do you have currently?

thsnks Inuyasha & Jett
I have an old school unlimited android plan that does not provide free hotspot. I was using the free hotspot only because TMO hadn't figured out how to block it....Well now it appears that they did....but only on chrome, not firefox.
I'll keep usihg the free app that works around TMO's block till that fails , o I have to pay for the "pro" version.
Unless anyone out there has a better solution.

Which data plan do you have?  There was a promo data plan that had the Smartphone Mobile HotSpot for free that ran earlier in the year(started toward the end of January), and that one should not have any problems acting as a wifi hotspot.  My data plan is Unlimited - Premium with Smartphone Mobile HotSpot Service(the promo plan, jumped on it when it was being offered for the same price as the regular 5GB data plan.

When I got the HTC One S, that is the plan they gave me. I love it! I'm not a heavy tether user, but I'm glad for when I do need to.

@doug - you may also try entering a new APN on your phone.