Non Consummation of marriage since 1.5 years

I am a working woman & had an arranged marriage 1.5 years back. My husband never showed any interest in me & never initiated any kind of physical intimacy. Rather he used to spend the whole day with his adult sister in her room chatting, laughing, caressing, hugging, etc. Even at nights, he used to be with his mother/sister till 1, 2 a.m. everyday and then come to our room & sleep. Neither he nor his parents ever bothered to correct this situation. When i confronted them on this, they said that they only wanted a daughter in law who would do household chores and any relationship between me & my husband was secondary. I told them that I can't continue this marriage without any conjugal relationship. My husband said that he will give me divorce but not return the jewelry that I received from their side relatives during marriage. I am not sure if my husband is impotent/ gay/ has some relation with his sister. Pl. suggest legal way out as I am under terrible mental trauma because of this.