Unless you can prove the 1st tier tribunal made an error if law you can’t go anywhere with this. Your only option would be to wait & fill in change if circumstances & try again this time with professional help.
Not calling anyone out or anything but no one should go to tribunal without professional backup & unless you get lucky with a hood can I wouldn’t include those in that category as there are far too many cab’s that aren’t up to the job.
I used fightback4justice via Facebook they were incredibly, worked on no win no fee & when I won charge was a few hundred from my thousands in back pay.
Without knowing more both myself & about your case I wouldn’t attempt to advise but I do know you can only go to the next tier tribunal on a point of error in law interpretation. Y the lower tribunal.
All I can suggest is immediately get help with this. I’d strongly recommend anyone offered a phone tribunal to refuse if possible even if it means waiting longer, like phone assessments it’s a minefield.
Good luck