Hi Eileen
Welcome to shelled warriors, and to someone else who is from Kent, I live in the Maidstone area.
Although your new tortoise had a rubbish diet fed to them, if he/she has had accsess to a garden, I am sure he/she has had the pick of plants and weeds to eat. So hopefully it was not all bad
Lots of friendly folk on here willing to help where they can.