Refusal to acknowledge my unsubscribe request

I had a corporate user account with LexisNexis which has expired, yet they are still sending me emails daily. I've requested several times to be unsubscribed from their mailing lists yet none of my emails have been responded to or actioned.<br> <br> I cannot follow the link they provide to unsubscribe myself since my account is no longer active. I just want to stop receiving any emails from them.