On the contrary

Our Airbnb hosts speaks English well, which would be helpful if he were helpful, but occasionally he gets expressions wrong. When I said thank you, he meant to respond, no thank you. 

Instead the conversation went like this

Me: Thank you

Host: On the contrary and have a good night. 

Me: Yeah, good night. 

PS - He has been helpful about a number of things, just a couple of areas where we could use his assistance, like the name of a cleaner and having a desk or some surface to write on. Other things, he has been really good about.