Cars24 Services — Car sale: party peshi not paid on promised date

Address: Ground Floor, EN 66, near Dugar Honda, EN Block, Sector V, Bidhannagar, Kolkata, West Bengal 700091

I have sold my vehicle to cars24 on 9th march and handed over my vehicle on 13th march. Terms and conditions were that that cars24 will pay rs 10000, within 120 days from date of delivery. They hold this amount to ensure that i am present during transfer of ownership at rto. Even if the car is not sold to anyone else, the amount would be transferred to me by 120th day. Now they are saying because of covid19 rto was closed for 70 days and hence they will be able to be transfer in another 84 days.in the original sale agreement there is no mention of such clause and they are holding back my money. I have sent multiple emails and even spoke with the manish dey (Sales representative) in the office.
They do not reply to email unless escalated and after that they closed the issue stating that it is resolved without paying me the balance amount. Manish dey, the executive is saying that they cannot pay the money because transfer of ownership could not be done. If transfer of ownership was the criteria then they should not have told me that within 120 days the amount would be transferred or provided the date of 11th july in the attached document. He said specifically even if the car is unsold after 120days, cars24 will transfer the remaining money of rs10000 as mentioned in the attached document from cars24.