Ion Exacense Pvt Ltd — cheating in the name of eureka forbes & not honoring the amc contract (condition 16)

During my service renewal ion exacense executive called me and informed me that they are sister concern of eureka forbes and they do amc on behalf of eureka forbes. I have taken 2 years amc from on 18th aug 2019 by paying rs 8530/-
They have changed the filter candles and post which the system stopped working. From oct onwards i have been following up with them, over mail and phone (Call records available) and there were no response.
Finally they came in the month of dec 2019 and changed the adapter, post which it worked till next day and after that it stopped working again.
I have called them up repeated times to get it rectified, but there was no response.
When i called them for refund, their response was that, since it is 5 months over, they cannot provide me with the refund.