Can you get banned from buying games from CdKeys

Hey there lovely people!
Apologies that it took me some time to jump in here. I can see that a response from EA Help was shared in this thread already. Just to reiterate that point:

If you are considering to buy codes from retailers other than EA (Origin), I would recommend you take a look at this EA Help article that has a lot of useful info on this topic - this is the article that the agent in the screenshot linked.

As was said in the chat, it is absolutely up to you where you buy your codes. But we do ask you to be cautious so you can avoid unpleasant surprises which is pointed out on the website:

What about other PC digital retailers?
Purchasing EA PC digital games from unauthorized sellers holds a variety of risks. The following information can help you protect your account and yourself.

Our games are sold at various online and in-store retailers across the world, but sometimes these retailers are not all they may seem to be.

Some unauthorized retailers bring risks with each purchase you attempt to make, and they can put your account and personal information in danger. Make sure to protect yourself:

• At best, you might get the wrong product or language version of a game you buy.
  
• At worst, unauthorized websites may be phishing for your EA Account or payment information. This can result in losing access to your account or fraudulent activity with your payment details.
  
• Additionally, any illegally obtained games and Product Codes will be disabled by us, and access to the product will be lost.
  

We want you to have the best experience, but we cannot help out with purchases made through an unauthorized digital retailer.

If you purchase EA digital products from an unauthorized party and the CD key or Product Code is disabled, you will not be able to play your game and we will be unable to assist you.

I hope this helps and confirms what you've found out by now. :)