module – Magento Observer to block spam requests that do not work

I am facing some problems with the orders placed by the robots.

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I noticed that all orders are made by a specific phone number and also by a specific street. So I looked for a way to block orders that are made with that phone number or this street.

I found the following link https://www.ashsmith.io/2012/12/making-use-of-observers-in-magento/.
I followed the steps to create an observer with the sales_order_place_before event, to compare the parameters sent in order with the parameters that I want to block.

  1. I created the file Blockbots_Observer.xml in / html / app / etc / modules;
  2. I created the Config.xml file in / html / app / code / local / Blockbots / Observer / etc;
  3. Finally, I created the Observer.php file in / html / app / code / local / Blockbots / Observer / Model;

After all these steps, the implementation did not work (I'm still receiving bot orders).

Here is the code in the files:

Blockbots_observer.xml:
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Config.xml:
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Observer.php:
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What could be wrong with the implementation? Any idea how I can fix it?