Marley's eye removal

My son who has additional needs' therapy cat, Marley, has had to have his left eye removed due to an aggressive tumour on his iris. This was life saving surgery. Despite having insurance in place, they have refused to pay anything towards it. Any donations would be gratefully received as I now owe the vets a substantial amount of money. Following his surgery, Marley is now making a really good recovery and adjusting well with one eye.