Service Delight — AC not repaired despite repeated complaints and over one month

I raised a complaint DEL[protected] on 28th August for repair of my AC which had stopped cooling. It took the team 3 days to get back to me despite their SLA stating a contact within 48 hrs. Then they visited and looked over things and said that motor needs to be repaired so another engineer will come next day and look over things. The engineer came next day and said that the motor they need isn't available with him and they will need to get it from the warehouse which should take couple of days. Since then, they have been postponing the repair citing various reasons like "Wrong model of motor", "correct model but doesn't fit in slot", "motor not available", "Need to get the motor manufactured at plant" etc etc. The service engineers and warehouse guys don't respond to calls or messages. Please help me out in understanding what I am supposed to do and whom to contact???