Osmania University — OU not releasing OD after application & payment

Respected Sir/Madam,
I've applied for my PG Diploma Convocation Certificate on 08/11/22 in Urgent Mode Via Postal Delivery and my receipt number is MB[protected]. It hasn't been delivered yet and when I contacted the support either they don't reply or they say we cannot send it and talking ugly & rudely on call.
Kindly look into it and do the needful as soon as possible.I expect my university that I've studied in should not be treating me like this after charging me.
Thanking you.