I did think of contacting tmobile but I'm not 100% that's who it's with I have put my O2 sim in from my iPhone and it says invalid sim and I hate orange after there customer service I've had in the past :-(
Get a wireless hotspot that takes the sim...http://www.amazon.co.uk/Unlocked-Wireless-Modem-Huawei-E585/dp/B003VHT37U/ref=tag_stp_s2_edpp_url
Use any of your devices through wifi. One option.
Also, if it's a network lock then to the best of my knowledge Orange and T-Mobile are not 'the same'.
i.e. if it was locked to o2 then it wouldn't work on Voda just because they use they same frequency.