Hi,
You will need to reach out to that particular server's owners/administration team to sort this one out.
It might be possible that you didn't enter the password wrong that many times, but someone with malicious intents could have, therefore blocking your account. This is pure speculation though based on what you've shared in this topic.
Restarting the game or changing the network, as you already experienced by yourself, wouldn't work. This is not an issue with MTA itself, nor with your network, but rather with your account status on that server, hence why you should address your support request to them.
Good luck on your endeavours!