hello just wondering if any investors out there have much...

hello just wondering if any investors out there have much knowledge on dividend entitlements. i purchased asx shares on 5/9/18 the day before ex dividend day being 6/9/18. record date was 7/9/18 and pay date 26/9/18. my trade settled on 7/9/18 at 11.00 am as i got a confirmation statement from cmc. i rang the share registry today link market services and they said im not eligible because they can only see that the trade settled on 10/9/18. they told me to contact my broker cmc markets stockbroking. i rang cmc markets and they told me im not eligible because the settlement date was after the ex dividend i didnt agree with this because i bought the shares the day before ex dividend date and it has always been my understanding i am buying a share cum dividend. i also emailed cmc and got no response. im confused and now dont have confidence in buying a share the day before ex dividend day. has anybody else had any bad experiences with cmc markets as im thinking of transfering my other holdings to another broker and not using them again.