[texas] Employer Agreed To A Raise In October, Paperwork Signed. Still No Raise And Claiming Its Coming In January.

Posting on behalf of my brother.

He works in a warehouse in Texas. In October, he gave notice due to dissatisfaction with the work/pay. They offered him a higher hourly rate to stay. He accepted and signed an agreement. He did not get a copy of the agreement.

He has not received the promised raise. Upon confronting his boss, the boss claims that the raise wasn't given because they're "planning to give him a bigger raise and title change by January 10th." My brother agreed and also asked for a copy of the agreement he signed in October. But wouldn't you know it - they "can't find it."

The above conversation happened on the phone today and not in writing. He threw up at work due to the stress and was allowed to leave for the day. He's worried about retaliation for leaving work today, even though he was excused. How should he proceed to ensure (as much as possible) he doesn't face retaliation and will receive the raise? He is considering sending the following text to try to get something in writing:

"Hello [boss] - Just wanted to follow up with a message to make sure I understood our phone conversation from earlier today. The reason I was not given the raise agreed upon in October is because of your intent to to provide a better raise (to $21.30/hour) and title change to Senior Tech by January 10th. I agreed to that adjustment and look forward to the raise and title change. Please let me know if I may have misunderstood something. I also wanted to thank you for being understanding of my not feeling well and excusing me for today. "

I have plenty of thoughts on how he generally bungled this so far. But looking for where he can go from here to protect himself legally.