My manager told me we're not supposed to 'advertise' this but... hey...
You can get free refills on any hot drinks I believe! (not 100% sure about hot chocolate!)
but tea, white / black coffee, cappuccino & Latte's you can!
White / black Coffee- £1.09
Cappucino / latte - £1.39
Tea- not too sure...
but if you 'go large' you have to pay a wee bit more, about 30p that goes with extra value meals (medium or large!)
and to top this all off! For the 6th cup you drink (can be either cappucino, latte, black, white, tea or hot chocolate) you can hand in a voucher (a sticker system) to receive a free drink!
Something else I should say is, With happy meals you can get hot drinks, considering the happy meals cost £2.19+ it's a pretty good price! :)
hope this helps someone!
(I should say, this might not be valid in every restaurant, but it is in mine which is a service station!)