a lawyer suggested call 1800 number ask for

a reference number, saying i receieved my approval letter
but no I-797 form with I-94, the USCIS will send the
reference to the center and take care of it.

I think this lawyer's point is to consider this is a
mistake by CIS not sending me a I-94 and ask them to
fix it by sending me the I-94. He says the whole
purpose of status change application is to obtain a
new I-94 without having to leave the country.

Will this work?