Welcome to the wonderful world of "someone will call you back sir/madam"
Your brother needs to make a decision-go with a company who can't even treat a potential new customer with respect, or look for another provider.
If the 150k service is in your brother's price range, then Tiscali now offer a 150k BB package via ADSL for £15.99 per month (see my post here on switching providers
here)
Tiscali link
HTH.