Petition ending Jan


I am not in US and would like to get some clarification on my petition.

I had applied for H1 B in 2014 through company A.My petion got approved in that year(2015) and this approved petition in the petition form ends on Jan 2018.

However on repeated followups company A did not show any interest till date(Aug 2017) for stamping.I now would like to know my options

A.Can I transfer this petiotion to company B? If so should this approval complete before Jan 2018? Is this possible?

B. Can I get this petiotion approval end date extended?

C.Travel to US possible only after stamping(either through Company A or B)?

Thanks in advance.