Lyceum bad service

Where can I report lyceum College? I'm a 3rd year student. I have submitted my assignments in Jan 2021, and subsequently resubmitted them about 20 times as they admitted they lost them. In the meantime I wrote exam, did my practical and got all but 1 assignment result. Started to query again only to find out they lost It AGAIN. IT HAS NOW BEEN ALMOST 3 MONTHS SINCE I RESUBMITTED IT. Everyone at lyceum is not answering emails or calls so I get no answers. I cannot get my diploma without that result as it shows incomplete.

Please I need help as to where I can lodge a complaint or get help.