tax payment made at wrong PAN no

very very difficult.
You will have to pay again in your PAN as without that you won't be able to file return.

file rectification application stating the mistake in payment of SAT. the wrong pan in which SAT has been paid doesn't exists then no problem, immediately the tax amount will be credited in to your pan if not the jurisdictional AO of the wrong pan has to certify that the wrongly paid sat is not consumed.

very true that process is time consuming but at the same time return filing you can not delay