After sales support

It's been 4 days waiting for the delivery of my cell phone their support it is an insult to support teams they reply after business hours their WhatsApp line is useless they should do away with it actually I changed the delivery address and on the second day and yet 2 days later they telling me I need to verify the change of the delivery address once again rentoza offer amazing deal but they are absolutely useless when it comes to after sales support its actually nonexistent?