"and the proff is that my telephone is working"

So why are you telling us that it's not working?

As I've said before, just because something hasn't (yet) displayed a fault doesn't mean that it is right!!

"i can not dial any other number on the exchange."

What precisely do you mean by "cannot dial?"
Are the correct tones generated? IF you say "yes", how have you proved this?

"pls don't tell me that my circuit is not generating other tones."

Well, Is it?
How have you verified that it is correctly generating other tones?

"i'm not good in analog affair..."

Then you should NOT be messing about with phone line interfaces - and certainly not on a live public network!!!
The PSTN line interface is very definitely in the analogue domain, and with some very specialised requirements - not to mention some potentially harzardous voltages.

"let me know if there is any differene between DTMF levels or durations what my circuit is generating and what is required on the telephone exchange in pakistan"

You have the circuit, and you have the requirements document. Did you not measure these things before connecting to the public network???!!!