My Landlord is being unreasonable for charging me an NSF fee.

[Judy Doolittle]

Hello, I am 68 years old and I am on the housing hud voucher program.  My apts who is managed by a real estate business has us pay our rent online what is called Realpage. I had brain surgery and my sister was my social security payee and had been paying it. I finally got to have my on SS check and this was my very first time to pay my own rent online on the Realpage. I accidentally paid a duplicate payment which at the time I did it I didn't even notice that I did. Realpage had no instructions and I was struggling to pay my rent anyway. I paid my rent on the 3rd like I do every month. I wanted to ad I have been living here for 7 years and never once been late on my rent. On the 5th I checked my bank balance and I had some checks bouncing and I panicked. I looked an sure enough there were two 379.00 payments on the same day March 5 they both cleared. I called my apt right then and thought that they would just simply return the duplicate payment. Nope and the mgr commented well now you don't have to pay rent next month. I told her I could not afford to pay to months rent. So I called my bank and explained and they didn't charge me and just reversed the duplicate payment.  When the apts found out not only did they charge me a 75 dol NSF fee they also restricted me from paying my rent online anymore. I have no car and I have to walk over a mile to get a money order for my rent. I told them keep the 75 I made a mistake but don't bar me from paying rent online it was not a nsf I canceled it. On my lease written in on paragraph 6 it states 1 NSF fee and then I would have to bring a money order in. I have cried and cried how can they get away with this. I have no one to advise or help me and I do not know if they are right are I am right and  if they are wrong what can I do.? I am thinking about talking to my case worker at my housing office but she really has never been any help. I made a copy of my bank statement showing the two payments cleared my bank and I made a copy of my lease to where it states 1 NSF fee. It doesn't say returned ACH Or returned check  for any reason on my lease it specifically states NSF which is insufficient funds. Does anyone think what they are doing is fair and if anyone has any information for me as what can I do. I feel like I am living in the twilight zone with these people I have been a good resident for 7 years no late payments no returned checks. I know this doesn't sound that important but for a 68 year old lady who is not well walking over a mile to and from the store to get a money order because I paid a duplicate payment. I apologize if I repeated myself I am just so upset over this mess. It is the principle of the thing.?  thank you