Amaron — Customer service center

It's not been 1 month after buying new inverter ups and it's complaint. When I registered a complaint the message arrived that they will contact you within 48 hours, they didn't contact after 48 hours they called and came to home, then they said the ups board as gone and they will change it 2 days. Now the time they said is over and they have not contacted yet when we call them they say that the don't have stock or some reason
I can't understand why they are doing like this
Very bad service from amaron
I believed amaron is a good brand so i bought batteries and ups from them
Please fix our issue or refund or money