can child support freeze a persons account if they are not legally marry

I have a joint account with my boyfriend we have kids together so I put him on the account in case of en emergency. He does not put any money in that account. He went to child support and gave them prove that the account is mine not his.They told him the they release the account and that they send a letter to the bank so they can release it. It has been more then two months and still my account is frozen. Today he try calling them again the told him that they were not going to let go of the account for a year and that they going to take another $800 out of the account. I got evicted cause I couldn't pay my rent do to this issue.