Hyundai Motors India Limited - Price surge after booking

We booked Grand I** Nios Asta Amt on ** April (Saturday) in the name of my husband Vivek Agarwal by paying the booking amount and submitting all relevant documents like identity card, address proof, salary slips (for availing corporate discount). We also received acknowledgement mail for this. Bengal Hyundai (dealer in Park Street, Kolkata) told us that they have a ready car which another customer has cancelled the booking for and therefore, the car will be delivered to us in **-** days (which is generally taken for number plate). Therefore, there will be no waiting period as in case of other cars and there will no surge on price after booking. We clearly told the salesman that we will be availing car loan and for that we were provided reference of SBI executive. Later on *nd May (Monday), we got a message from salesman stating that the ex showroom price for the car has increased by Rs. ****.
*. How can the value of a ready car increase? We did not give order for a special customised car and therefore any increase by manufacturer is not apprehended since the car which was shown to us in the showroom was not being re- manufactured and we were only taking possession of ready car.
*. The salesman told us that since we have not availed loan yet, therefore, new price is applicable. There was a holiday (Sunday) in between the booking day (Saturday), and the message day (Monday) when it was communicated to us that price has been increased. We had submitted all necessary documents to the salesperson and the booking confirmation mail was also received, how can there be a price surge once you book the car. Have the dealers heard of the concept of offer and acceptance in the contract act. You had offered us the car at a particular price, and negotiation, we booked the car and accepted your offer. Is this not breach of contract?
*. If we book the car through some other dealer also now, we might have to pay surge amount, who should be liable for the differential amount? Further, there will be a waiting period on the car, should the dealer not be liable to pay us damages? We had clearly told the dealer that we need a car urgently because my husband has to go to various sites and during rainy season, driving of * wheeler is not comfortable. Therefore, we agreed to take Asta model beyond our budget (originally we had thought of Sportz AMT, which was **k cheaper). Further, we should also get compensation for deficiency in service and the mental harassment caused to us.