Sneezing kittens

I got myself two free kittens off Facebook on Christmas eve. the boy mustang came with sneezes and his little sister has some on occasion. I have dealt with allergies my whole life and know that his are worse than mine. I have taken them to the vet 3 times and we have tried two types of antibiotics and the sneezes just come right back. I have suggested allergy medicine the last two times but no such luck. I have had them for 8 weeks now and they are happy and the chillest cats ive ever met. I am not looking for medical advice just wondering if anyone has ever dealt with something similar. I just dont have the money to keep taking them back with no results .