Let’s analyse their relationship from the beginning.
Their first meeting was a complete disaster. Roshni was being a prat and Aman responded with excessive force. Sane people do not total another person’s car because they bumped into them. This is a tv show moreover a magical one, so let’s call that creative liberty for arguments sake.
Aman discovers Roshni is Ayaana. Ayana by description has the heart of an angel. Bare in mind that Roshni does not know Aman or his family beyond her short interactions with him. So why on earth would she come to his aid , when he calls her for his mother? She does not know she is Ayaana, she has no clue of the fact. Aman found out her mother is a courtesan and saw her dancing, so he naturally assumed she is a courtesan? But where does that give him the right to abuse her character. He expects her to help his mother and then goes on to abuse her. She has never to his face asked for money or spoken like she wants to benefit from him. Aman is making judgements about her nature and abusing her based on his and his mother’s assumptions.
Lack of communication between leads is the usp of most ITV shows and here it is no different. Even then, Roshni has no reason to open up to Aman or trust him about matters. He uses her when needed and discards her afterwards. No one in their right mind would keep anything beyond a formal relationship with such a person.
So yes, for me, mistakes have been more on Aman’s part than Roshni’s.