The organisation, called Us, set up the centre on the island of Lesbos and provides food, shelter and medical care to people.
It was only possible to create the centre through people's donations.
They also bought safety equipment, lighting and tents, and paid for the construction of huts and a kitchen, as well as petrol, firewood and food.
Proceeds from the Us Rapid Response Appeal were given to Lighthouse Refugee Relief (LRR), which set up a the sanctuary on the north-east of the island - a place where hundreds of refugees are arriving daily by boat.
LRR volunteer co-ordinator Henry Hartley said: "The immediate effect of providing help to those arriving at night was obvious.
"Our presence meant security in the area was tighter, and slowly all the 'opportunists' left the area.
"Also, because of our night time presence, the teams during the day could start building infrastructure knowing that theft is no longer a problem.
"In the space of a less than eight weeks [since we arrived] the Korakas area has been transformed from a horror story for anyone landing there to being welcomed and received by a dedicated team of volunteers and medics."
Suffragan Bishop in Europe David Hamid said: "There are huge needs, particularly concerning unaccompanied minors, pregnant women and the most vulnerable among the refugees."