Ok well if it’s normal, I would ask them how they can fix it with a repair? Charge you $89 to replace one clicking case with another clicking case? That makes zero sense!
I’d ask to speak with a manager. If they says it’s a normal sound, ask them, then why did the genius want you to pay to get it fixed?
I will try it in another Apple store today, don't have big expectations however.
Have ordered a dbrand skin for the charging case, maybe it will reduce the clicking at least.