Employer refusing to pay relocation allowance as mentioned in offer letter

Dear Experts, I recently moved to US from India on Blanket L1 Visa. My employer in India informed me that they are moving me to US only five days before US joining date. I came to US as instructed.

As per offer letter that I accepted, I am eligible for USD 5000 relocation allowance and can claim reimbursement for hotel stay for first three weeks. The offer letter refers to a policy that allows me to bring my family to US at company expenses and several other monetary benefits.

Three weeks after joining, the HR refused to pay relocation allowance. When I questioned their non-compliance with my offer letter, they sent me a new offer letter.

I have already spent several thousand dollars in hotel and other expenses - all as per policy and my original offer letter). As per revised offer letter, I am not eligible for any relocation benefits (even though I remain on US payroll) - including relocation allowance, hotel expenses for first three weeks and family travel.

I have refused to accept new offer letter as it is not in compliance with any company policy, I asked for a policy according to which a new offer letter was drafted but they didn't provide an answer. All they said that it was decided by a finance vice president that relocation allowance and benefits are unnecessary expense hence employees should be given offer letter without mention of it.

They had given me original offer letter to show to VISA officer at the time of L1 interview and to immigration officer at the time of entering the US. They are not only violating my offer letter but also violating well documented company policies that I accepted while joining in US. What legal actions can I take against this employer for not complying with offer letter terms and conditions?