Reliance Digital Hitachi - Reliance Digital Aircon Installation team damaged our electrical pipe inside the wall while drilling

We purchased an aircon with Reliance Digital Indirapuram at Shipra Mall on **th May ****. The installation team visited on the **th May ****. While drilling through the wall they damaged the electrical pipe inside the wall badly. It was promised to me by the installation guys that there is nothing to worry about it and I requested them to send me an email on the same so that I have a written confirmation from them. And its been now approximately * months and all that reliance has done is fake assurance over the many emails i wrote to them and many calls that i made. I dont know what should i do now. I am worried what if in future this thing will give me an issue and i will have to spend lacks in repairing all the electrical wires inside the walls.

Also the intallation team charged me an amount for which they promised to send me an invoice in the next working day as **th May was Saturday and the insallation happened in the evening. It took them almost * months to give me the invoice and that too was an incorrect invoice as the amount was not the same that i paid to the guys.