H1 transfer to client company, did not join, client generated paycheck

[johnyg07]

I transferred my H1 to client. The h1 transfer was approved. It was premium processing. But my employer did not let me join because of non-compete.
I continued as contractor at client with my original employer. But client already on-boarded me in their system, and they sent me paycheck for 2 days at home.

can someone suggest me how to resolve this complicated situation? I will not deposit the check and will return to the client. but i think they will still send me w2 at the end of year.

I did not terminate employment with old employer and I did not fill I9 for the client.