Pret A Manger in London has more and more Vegan varieties! If you talk nicely to them and tell them you are a vegan they will offer you a free milk replacement! And sometimes, even a free coffee! Their staff are multilingual and very friendly. They have a number of different vegan milks. My favourite is Soya Milk, my son's favourite is Almond milk, my husband's favourite is coconut milk, and they are all free and they taste absolutely great!
Their website navigation is very easy to use, even a child can use it, or an elderly person can use it, you can also order online or find an address near you.