Banned account...why??

Today I got this email...they closed my case:

We got your note and did a full investigation of your account. After reviewing your case, we determined that we took the correct action in accordance with EA policies and procedures.

What this means

We have confirmed that your account was involved in cheating. Because of this, we will not remove the sanction on your account.

You break our rules(https://www.ea.com/terms-of-service#section6) if you:
• use software that interferes with or disrupts an EA Service or another user’s account.
• use undocumented features, exploits or cheats in-game that disrupts an EA Service or another user’s account.
• use software or cheats that disconnects other users from the EA servers.

So...still no details about how did I cheat and how they eventually found out or what a full investigation means for them ("you break our rules if you"....).

I don't know anything about that.

What do I know:

1) I didn't cheat...I hate cheaters and I always reported them when I could;

2) it's a free game but I paid money to unlock seasons and legends and if I did it it was also to support the developers because I thought they deserved it...now they'll keep my money?? ok...some people say they do it on purpose to make you pay more money but I don't believe it of course;

3) I like the game and I'll do another account maybe but I will not pay for any legend or season this time because I can't know if mistakes like this could happen again in the future...so yeah..I'll just use the "basic" legends;

4) this forum and the support team don't give informations;

thanks EA