Jawed Habib Hair And Beauty Salon — No bill provided for service. Extra Amount Charged. Treatment done without prior approval

Address:	Jawed habib, DLF newtown heights, Kolkata.
Website:	jawedhabib.co.in

On 27th Feb, 2021 I went for keratin treatment and ozone treatment. Without my knowledge they did some dandruff treatment, the cost of which I was ready to pay but they charged me 1800 instead of 800(actual charge). On top of that, I wasn't even provided bill for the service after paying 18% GST which is odd. After researching, I found that I am not the only one who has faced this in this particular salon. There are many others with the same issue.

Also before providing the service they told me that they would give me some discount because of which I agreed for the ozone treatment but they didn't. On asking for bill, I was told never to come again there.

My problem is that first I was given a treatment prior approval and was then forced to pay extra amount than the actual service fee. Second, I wasn't provided a bill from the salon. As a proof, I do have the customer copy of my debit card's receipt.
Third I was mistreated and this behavior isn't specific to me. They treat many people like this post services to humiliate and force them to pay. (Proof is in google reviews of this salon)
Fourth I was charged too much although I was told that I will be given some discount.

I want refund for the service I didn't request for and the extra charges I was asked to pay. I also need a bill for the service and change of the staff specially the one named Sudipta.