Voltas — Voltas AC cooling issue and servicing

I have voltas ac which I repaired with new parts in March 2020. People from Global Home Appliances, Vaishali did the repairing. I reported issue on the issue as it was not giving the cooling effect. I complaint to them few months back but because of lockdown, nothing happened. However this october month I asked them to visit and check the issue and they scjeduled a visit next day but did not turn up. Since then they are not answering my phone calls.My october 2020 warranty is nearing end now and need immediate addressal.