Does it cost to send/recieve texts from twitter ?!?

if your on T-mobile you can see other peoples updates from your phone, you cant do that on vodaphone. however you can update from your phone by text, although i have unlimated texts but it still costs me, but not much only like 10p and if your in the U.S/Canada then its like 10c im guessing. but anyway to get the number for twitter you have go to on the website and go on devices there. it will tell you how to do it on there <3