Need to SECURE and PROTECT EA from Hackers

We have an EA business that sells high performing EA systems to clients. 

Right now we have the following securities in place :

- Account validation
- Expiration

However, hackers have still been able to hack our EA and remove these functions to create unlimited version of our EA and give it away for free on the web. 

We have considered doing a trade copier and sending signals to an EA that validates users accounts and can receive the signals from our separate server, however we're not sure that this is legal in the US. 

We are searching for someone who can help us protect our EA against future hackers, so no one can hack, steal, decompile or reverse engineer our products ever again. 

For obvious reasons we are not comfortable sharing any source code, however, we are willing to meet on zoom calls or whatever is necessary to set up the security. 

We are open to any suggestions.