Customer support - Req fr system where author has to reply within 48 hours, atleast for paid support

I dont want to say any names but its a request from my side that authors atleast for those we pay to get support do atleast reply within 48 hours. Or else a feature that lets us know that author is not available for support and we get extension of support atleast for the days he or she is not available for support. Customer has to wait weeks for getting support from author or their team.