Bad customer service

I have been waiting for my clearance certificate for an unreasonably long time, and the level of communication has been extremely disappointing. Responses often take weeks, with little to no proactive updates. Initially, I was told there was a backlog, which I accepted. However, I am now being told that my clearance certificate was sent and that I should check my emails. I have thoroughly checked my inbox, spam, and junk folders and have not received it. Despite the status showing that my clearance certificate has been issued, I am still waiting to receive the actual document. The lack of communication and delays throughout this process have been incredibly frustrating.