It doesn't matter you signed or not.
Reject a offer is very easy. just a simple phone call will make the job done.
Don't go to the work just because you have signed.
Don't reject the good offer just simply because you signed another one first.
You always choose what is the best for YOU and YOUR family.
Salary, LifeStyle, marketable skill sets are the three conditions I choose an Offer. No other conditions. Sign offer letter or not is NOT a condition.
