Just ask them clearly why its not transferable. May be we have to wait some more months to change it.
Some visa cannot transferable if company is having some problem or if the labour approval for visa is finished (may be only one year labour contract) If you get the clear idea ,then you will get the answer from here..what to do next..!
If you get NOC from your sponsor, you can cancel the visa and comeback next day with another visa. Ask the other company they are ready to give you new visa.