EUREKA FORBES LIMITED - Prepaid Service Complaints not Attend

Dear Sir/Madam,
I would like to inform you that, I have a purchased Service & maintenance AMC from EURAKA FORBES LIMITED (Formerly Forbes Enviro Solutions Limited) for my Aquagard Enhance UV+ as on **.**.**** vide Invoice no. ************, and booked for a *st service of my Aquagard as on **/**/**** as per Service request number CM-******-********, but till date they not sent any professional in my room and not repair my instrument. Since **/**/****. I have been continuous followed up with their C.S.C number alongwith my booking details but no solutions come out from them. Almost Eight to Ten times I was talked with Customer care center (***********) every times they told me that it will solved soon but they not assigned any professional for my service request I also mailed to them but they not replied. I was asked to return my payment but they told me that it is not possible.
I was purchased the Gold AMC from them as per their assurance over phone that no complaints will come out from our end related service and they sent a payment link and I was paid Rs.****/-. After payment e they sent an Invoice to me (attached the Invoice).
I am facing very big problem alongwith my family, due to absent of drinking water. So I choose a last option to inform you for my justice.
Hope you may do the needful for me.