Marriage call off

Hi I'm Karthick , ( groom is from media background) My sister got engaged to a guy & engagement happened with everyone's acceptance & aftr engagement the groom started to behave wierd & he is not stable in anything & he said that he don't want marriage now & there parents has forced him to get married that's why I have accept to marry my sister & later on he was telling on my sister has she is zero percentage value for him in his life & she won't be happy if she married her . We have showed the messages which groom has send to my sister to his mom & they told we will discuss about this in person .. few days later they came & met us & we have explained it to them they told that my son won't behave like this in future & the groom told that he was in tension so that I told you so .. after that we started to print invitation ..later my sister messaged the groom stat tht do u like me really & do u like to marry me .. he replied her tht I'm ok with live-in relationship & not ready to marry ..& ur looking beautiful .. my sister replied him tht I'm not the kind of girl your looking for ... If u don't like to marry me just tell tht to your parents & proceed further .. later he replied like we don't want to talk now ....we I'll talk later after marriage my sister to ok .. 4 days back groom's came to buy marriage saree & we have asked her to bring groom but he dint came & never call and asked about anything ... Aftr we took the saree groom's mom took photo of the saree & went home .. aftr going home groom's showed the photo to him .. he dint say anything .. later groom's mom & dad started to native .. few minutes later groom messaged my sister like ... I don't want marriage now & there is no love between us & if it's end up with marriage I won't talk with you for life long & it will end up in divorce so pls talk to my mom & stop the marriage..( groom is not talking anything about marriage to there parents ) ... My sister fwd the msg to groom's mom she told like he is having waving mind ..don't take it serious I'll talk about it tmr morning ..but there was not reply on it by morning .. we have decided to stop the marriage ..due to character of the groom is not good & he is from media background only thing he want is money ... Pls suggest how to proceed further