Braintree Payment gateway integration Expert

My developers and I are tying to integrate Braintree to my iOS software and website, so first the client needs to register for a account, once registered they enter card details the client get a 30 days free trial and the payment begins after the 30 days free trial. Except it’s not doing that. The website sometimes crash after the card details is entered, the payment comes out straight away and the discount code does not work. We tried contacting Braintree directly everything they subjugated that we didn’t also work.

Is this something you can fix ?, I am looking for someone that will give me the results I need.