I ordered and paid for an air conditioning set on ...

I ordered and paid for an air conditioning set on 06/14/2020, unfortunately only the wall bracket has been delivered until today (07/22/2020). No answer to multiple letters "where my job is" and nobody can be reached by phone! I would NEVER order anything here again, certainly not with prepayment!
Which email address can you contact to get an answer? My order number is 312847