Rental company demanding more money a few days before move-in
I signed a lease and welcome letter detailing move in costs and rental concessions. I paid everything way in advance. I'm due to move in on Friday, and today I have been informed I owe $700+ additional monies as the office made a mistake with the original letter/ lease.
Communicating via text, I am not getting a clear answer as to the new breakdown of costs. I requested an alteration to/new welcome letter and was told that was impossible. I have now requested a formal breakdown of the new costs with an office letterhead, at the very least, and am waiting to hear a response.
This seems like incompetence at best and super shady at worst. What's my next steps if they continue to refuse documentation and insist on more money? I'm locked in to a lease, after all.
Location: New Mexico, USA