Parking issue. Allotment of same parking to 2 members/purchasers.

We booked a residential flat with a well-known builder in the city of Pune and got the position of the flat in the year 2018. At the time of possession of the flat, We were allotted a car parking with parking number UPPER BASEMENT- 314 and have the allotment letter of the same. Soon after some time, we discovered that someone else was also parking their car in the same allotted parking slot as ours. Upon enquiring we discovered that the builder had allotted the same parking to 2 people/owners. After bringing the same to the builder is notice, and after a lot of follow-up, they understood that they had committed a mistake and they tried to cover it up by saying the parking allotment to us was in the LOWER BASEMENT - 314 and not the upper basement We did not want any conflict hence we accepted the same and asked them to issue a fresh allotment letter in the current date with parking number 314 in the LOWER BASEMENT. Soon after receiving the letter and informing the same to the society office, to our shock, we learnt that the parking LOWER BASEMENT- 314 is also allotted to some other member of the society by the builder. Now there is no Proper response Or co operation from the builders side and also from the society side. Currently we are without any parking and we have to park the car in the open space/ common area. There has been much delay from the builders side and they refuse to Co operate for the reason best to the knowledge. We have been sending en number of emails and follow up and reminders m, but all unheard. In such case, kindly guide what shall we do ? Thanks in advance. Best regards,