Eureka Forbes — No bill has been received for service of my NOVA model

Address:	Mumbai
Website:	www.eurekaforbes.com

I have raised a service request(complaint number-[protected]) with eureka forbes customer care regarding the service of my aquaguard water purifier.The Executive has told me that you will get a call back from our nearest technician who will visit at your house and will change the filters.The technician has visited at my home address and informed all the charges of changing filters and labour charge.When i asked him about the bill then he denied.I immediately called back at customer helpline of eureka forbes and told them the whole situation.The executive itself said that just let technician do his work and we will send you the bill through E-mail.But it's 5-6 days now(on 12 June 2021) and i haven't received the bill yet.
When i called at the customer helpline this time, the executive clearly denied me to gave the bill.He said it's company's policy that we don't provide a bill to our customers for the service.When i told him that it's consumer's right to demand and get the bill for the service that he has paid for, you just can't deny me on which he argued with me and said it's company's policy.When i told him that i am going to proceed with legal case for this and you would definately be responsible for what you have said on which he asked me to be on hold so that he can raise a complaint and transfered my call to random person.
The name of the executive, to whom my call has been transfered, was sharaana.She gave me the same answer at first, then i told her that i am going to proceed with legal case for this and i will also mention your name in it also on which she gave me wrong instructions and cut the call.
This is how eureka exploits their customers.
Even when i have asked their technician, at the time of service, about the bill, he had denied me but after a long argument he said you have to pay 18% gst above on MRP, then i would give you the bill of any random firm.
How someone can ask me to pay gst above MRP because MRP otself is inclusive of all charges.
National consumer helpline is my last hope as i am feeling exploited and being mentally harassed by eureka forbes as their executive just put you on long hold ane even denies to provide the bill.It's a criminal offense which might be taken seriously.