Back in the day when i worked in customer service for a major telco it was completely standard, and was also part of the conditions that the customer must be told when they sign up for a new contract, it was also bolded and quite clear in the paperwork signed and if you signed up over the phone you were required to be recorded agreeing too it.

I regularly received calls from unhappy customers who had not been told when they purchased in store, so i used to offer them a credit for the months access in advance and submit a complaint about the dealer who sold it too them. DF, who still works for that company, was telling me just last night that they have changed it so it is almost impossible for customer service to credit a customer anymore though, there is no way i would have coped with my job if i that was the case for me, i used to credit customers left, right and centre!

Good luck! You could always try an ombudsmen complaint, or at least threaten them with one