I know game changer would have been a better choice for above mentioned context. However, still I want to know if using deal breaker was completely wrong at my part. please suggest
They have different meanings, it’s not possible from the small amount of context given to work out which is required.
deal-breaker - the thing that caused a deal/event, etc. to be rejected. The situation will not continue.
game changer - the thing that caused a deal/event, etc. to change. The situation will continue, but it will develop in a different way to that in which it was originally developing.
thanks actually context was something as follows - We score good marks. 100 satisfied surveys for general inquiry were responsible for that. Therefore I used the term deal breaker for them. However, later when someone confronted me for using deal breaker I felt that game changer was appropriate & thus should have been used instead.
‘100 satisfied surveys for general inquiries’ doesn’t make a great deal of sense. I think you might mean something like
It turns out that ‘general inquiries’ received a ‘satisfied’ rating from 100 survey-takers.
There is still not enough context to know what you are speaking about and which is appropriate. There is no way of knowing from what you’ve said exactly what you are speaking about.