Hatzola tweeted: “Kudos to this kind-hearted boy for his exceptional deed.”
Miles, parents Melodie and Stuart, brother Louis, 15, and sister Mirabelle, 11, enjoyed a celebratory tea and a tour of the call centre.
Charity representatives also dedicated a plaque to its benefactor.
“They were so grateful to Miles and are just the most modest and kind people,” Mrs Isaacs said afterwards. “They left an unbelievable impression on him and our family.”