Find out if there are any workers' rights clinics in your area where you can talk to an employment law expert about why you think you are being discriminated. If you are coming to the United States on a temporary visa, you may need to prove financial support.A sponsor can file the I-134 form. You can just make a simple table on a word document, and declare the remaining work experience that didn't fit in the 3 slots on the form, upload and send that. If you cannot obtain a letter, you should discuss with your lawyer what alternative forms of evidence you can provide USCIS. You must establish that you meet the requirements under U.S. law to receive a visa. Contact an Immigration Attorney Today.