You can check the reasons yourself first, such as whether you used a problematic IP address, whether you registered your account through normal channels, and whether you violated some official rules of the game. These reasons will lead to your Lol account being blocked. Generally speaking, If it is a normal registered account, if it is not a major violation, you will be given a chance, and it will return to normal after appealing, but there are also accounts obtained through other means, or permanently banned due to major violations.
Purchasing LoL Accounts through transactions is also a very common behavior, but the risk is relatively high. If you buy it from an unknown small store, the security cannot be guaranteed, and anomalies may be detected by the official during the use process. However, some large online shopping malls such as RPGStash are very reliable, because they will put the safety of customers first, and there will be professional people who register or upgrade LoL Accounts
through legal channels, so that buyers can be 100% assured. I have bought three game accounts here, and the longest account has been used for two years without any problems, so I would recommend RPGStash.