Help a lovely autistic boy stay in NZ

We are a brazilian family, my husband is builder and i am chef we are living for 3 years in NZ, after 1 year living here our son was diagnosed with autism! We have now been informed that immigration will probably deny my son's new visa due to his diagnosis! He is a lovely boy who loves NZ, loves hugs and kisses and is super smart! As we recently moved from Auckland to Queenstown we are unable to save the amount required to apply for the new visa! We are good people, we respect New Zealand and we just want to have a chance to be able to stay here! We have to pay the immigration adviser by 15/12/19 because our visa ends on 01/20/2020! our son is very well adapted here and he goes to regular schools! We do not want to go back to our country where inclusion in these cases does not exist, children with autism are denied places in regular schools all the time in Brazil! Please help us fight for our son! This is the appeal of a mother who only wants the best for her child's future!