Cashier generating multiple customers with the same email

This appears to be a coded bug in cashier. All my settings appear right.. Can anyone help?

Have you referred to docs?

Also show us your code and we can try and help.

Code is pretty simple, just a basic credit card update;

$user = \Auth::user();
$stripeToken = \Input::get('stripeToken');
$user->updateCard($stripeToken);
return 'ok';

Can you maybe post the updateCard() function here?

Sure, from cashier's billable class:

public function updateCard($token)
{
    return $this->subscription()->updateCard($token);
}

And from Cashier's StripeGateway:

public function updateCard($token)
{
    $customer = $this->getStripeCustomer();

    $card = $customer->sources->create(['source' => $token]);

    $customer->default_source = $card->id;

    $customer->save();

    $this->billable
         ->setLastFourCardDigits($this->getLastFourCardDigits($this->getStripeCustomer()))
         ->saveBillableInstance();
}

Ok, the error was that ajax was submitting the request to another route. After 2 days searching for this, I feel stupid. :(

Always something simple you've over looked, I do that on a regular basis, don't worry about it, just see it as a learning curve :)