Sarathi Parivahan — OTP didn't receive

Address: At. Mota sakhpar ta gondal dist rajkot

Website: sarathi.parivahan.gov.in

Dear sir,
I want to update my Mobile Number in Driving Licence. But didn't receive OTP in new mobile Number.
I talked with customers care he said u do mail at contact us.. but till now no any response of mail.
What i do... For update Mobile Number.
Why i not received OTP.