Custom Payment Gateway (Helcim)

Hello,

I was wondering if anyone else has integrated Helcim as their custom payment gateway?
Helcim API here: HELCIM API
My dev is having problems trying to use their API so that I am able to manage subscriptions with Pabbly.
Helcim requires that a customer account is created before it will allow for a subscription to be purchased - this would mean the customer information has to be entered in twice, which is a problem.
Also, it seems that Pabbly doesn't collect the customer's credit card information, so that it cannot be passed to Helcim. - They accept a link to our server or a link to the payment gateway. This link is also used for the rebilling...

I'm unsure of how we can successfully use this payment gateway. Any help would be appreciated.
Thanks.

Hello Scarlett,
We have reverted to the ticket you raised with us. Please refer to that once and let us know if you need further support.

Hello,
The person which responded to the ticket just sent a link to the integration docs. They didn't address my issue. I require specific assistance to the above mentioned.
Thanks.