support(at)zohoaccounts(dot)com how long do they take to respond

support(at)zohoaccounts(dot)com how long do they take to respond

I contacted support(at)zohoaccounts(dot)com today at 16:03 (GMT+1) because I am unable to add a new domain to my zoho account and the error message said to contact this email address.
Three hours later and I have received no response whatsoever, not even an automated acknowledgement of receipt. What is a reasonable length of time to wait for a response from a professional, paid for, service? I would say 3 hours is too long. I need to get email up and running for this new domain so when my plea for help via email was ignored I came on this forum only to discover that they won't discuss this issue on a public forum, for security reasons. So, email support is the only my only option, and they're not listening.
Can anyone tell me what waiting time I should expect. I don't even know if my email has reached it's destination, surely an initial automatic response can't be too much to hope for.

                            Zoho Desk Resources

                            • Desk Community Learning Series

                            • Digest

                            • Functions

                            • Meetups

                            • Kbase

                            • Resources

                            • Glossary

                            • Desk Marketplace

                            • MVP Corner

                            • Word of the Day

                                Zoho Marketing Automation
                                    • Topic Participants

                                    • alex

                                        Manage your brands on social media

                                                Zoho TeamInbox Resources

                                                  Zoho DataPrep Resources

                                                    Zoho CRM Plus Resources

                                                      Zoho Books Resources

                                                        Zoho Subscriptions Resources

                                                          Zoho Projects Resources

                                                            Zoho Sprints Resources

                                                              Qntrl Resources

                                                                Zoho Creator Resources

                                                                  Zoho WorkDrive Resources

                                                                    Zoho Campaigns Resources

                                                                      Zoho CRM Resources

                                                                      • CRM Community Learning Series

                                                                        CRM Community Learning Series

                                                                      • Tips


                                                                      • Functions


                                                                      • Meetups


                                                                      • Kbase


                                                                      • Resources


                                                                      • Digest


                                                                      • CRM Marketplace

                                                                        CRM Marketplace

                                                                      • MVP Corner

                                                                        MVP Corner



                                                                          Design. Discuss. Deliver.

                                                                          Create visually engaging stories with Zoho Show.

                                                                          Get Started Now