Indane Gas — Indane gas dealer not providing bill for payment made

Address:

H.No. 8-1-307, Vivekananda Nagar, Shaikpet Nala Golconda, Hyderabad, Hyderabad Dist, Telangana-500008

Recently I've applied for new Indane gas connection on 22nd April 2022 from dealer, they charged Rs.5000/- for new connection in which they provided a composite cylinder(a cylinder made of 3 layered plastic), connection pipe and a regulator. I made payment through PhonePe(Transaction ID: T2204221317283867111727). After payment they did not provide any bill receipt, instead they said "it will take around 10 days for receipt generation and consumer number creation". After 15 days they gave me subscription voucher mentioning the date as 29th April 2022(I paid on 22nd April 2022) and showed total bill amount as Rs.3500 only i.e., 1500 shortage to the total amount paid by me.
I've called multiple times to the dealers office but the landline was not at all working.
So visited the office on 4th June 2022 at 11.30A.M., there are 2 persons at office who did not know anything about new connection details, they made phone call to a lady and asked me to talk to her in the phone, when I asked her about the bill details she spoke in a rude manner and told me to wait half an hour in office. As I have other works I did not wait.

Also delivery of cylinder was late, I booked the cylinder on 30th May 2022 and I haven't received the cylinder till today(Dt: 5th June 2022), there is no proper response from dealers even for delivery also.