Moved In A Month Ago, Apartment Complex Possibly Lied On Lease.

Hello, just trying to figure out what my options are. Apologies if this is rambly, I’m a bit frazzled by this situation. In the lease that I signed, I was told that there would be a one-time base rental concession for the month of January, as a move in special. However, January has arrived, and rent has been charged— I had about 700 dollars in my payment portal, after a debacle in which the agent I was working with lost my security deposit money order, and that has been drained, and I am being told that I still have a balance due for rent. I emailed the apartment complex with an attached picture of the section in my lease detailing the concession, and received a reply from someone I have never spoken to previously telling me simply to check my ledger and that rent had been posted. I feel like I shouldn’t pay it until this has been straightened out— and even then, I signed a contract stating I would not have to pay January rent at all— but my roommate is simply urging me to pay it so that our credit scores are not impacted and we don’t face any penalty fees (except my roommate does not currently have the funds, so I would be the person to pay the rest). The leasing office has been sporadically open due to the holidays, and is apparently closed all day today. What can I do?