Thanks for the offer but I already Ordered one on Nokia Lumia 610 - White and got the Unlimited Text Booster changed to the Unlimited Landline by calling T-Mobile Customer Care. One more interesting fact I found on my T-Mobile Account online was it showed an £1.50 recurring discount on my new contract. Seems as an existing customer T-Mobile have offered me 10% discount on this additional line. Although will wait for the first bill to be sure.
BTW did you ordered any of these deals.
Is your phone unlocked and unbranded?