This is an automatic ban. You clearly have something of NetLimiter running or the files of the program is still there.Can you put your serial here, I can see if I can ask a MTA staff to see which files you need to remove.
I talked to a MTA dev, he said that C:\Windows\system32\drivers\nldrv.sys Netlimiter driver is loaded in RAM, thus its not removed correctly.
This happened to me once. I asked an admin then told me that this isn't counted as server punishment. My ban is because of CISCO lagswitch (software) as I'm using in my study. I suggest to not open the application that cause your ban while playing MTA.
Edit : Someone mention Pilovali as I replied to his post and there’s a slight chance that he’s the one who deleted it, not sure.
@Pilovali As Punjabi said, please check this topic, you might get your answer there: Click here.I will mention @UD07 as well because maybe he can answer your question himself.