Network Provider imob.tv spam problems - help !

i have just recieved a text from imob.tv saying

"FreeMsg: 1-week
complimentary calling
minutes available! To
claim txt: CLAIM to
87122.
Subscriptn3gbp/wk
Help08448714184
Stop?txt stop
UKlandline www.imob.tv"

anyone else had this mesage?

i was wondering if it will charge me as i havent signed up to any service what so ever.

Subscriptn3gbp/wk <-- that kinda gives it away m8 it will charge u 3 quid a week