title: Paypal recurring payment with update billing cycle
body: <p>I am using <code>laravel 4.2</code>. I am working on a project that provides video services. The requirement is to integrate the <code>PayPal</code> payment gateway with <code>recurring profile</code>.</p>
  
  <p>Although I had worked on creating <code>recurring profile</code> a lot using <code>PayPal classical API</code>, I've almost achieved my goal. But I am miserably failed to know that <strong>you cannot update a billing cycle's dates in already created recurring profile</strong>. </p>
  
  <p>Now I am feeling helpless. </p>
  
  <p>I've a project that provides video services to the users. The basic idea is, while sign-up, user select a subscription plan and insert <code>credit card</code> details. As it is a monthly subscription, the payment should be <code>auto-renewed</code> each month. </p>
  
  <p>In between, at some point if user <code>upgrades</code> the higher plan, then he will be <code>charged</code> for the <code>difference</code> of new subscription amount and currently active subscription amount for current month and his billing cycle must be updated from today to next month. </p>
  
  <p>For example, there are three type of subscription plan as below : </p>
  
  <pre><code>Basic for $10/month, 
  Economy  for $20/month and 
  Premium for $30/month
  </code></pre>
  
  <p>If an user has subscribed for <code>basic plan</code> on <code>1st May</code> for <code>$10</code>, his <code>billing cycle</code> will be set from <code>1st May to 1st June</code> and so on. Each month he will be charged for $10 automatically until he unsubscribes or stops recurrence of his profile. </p>
  
  <p>Now, in-between on <code>5th May</code>, he upgrade his plan to Economy (that provides more videos) having <code>actual amount of $20</code>, he will be <code>charged for difference = $20-$10 = $10 for current month</code> (i.e. <code>May</code>), his <code>billing cycle</code> will be set from <code>5th May to 5th June</code> now and he will be <code>charged $20 each month from 5th June automatically</code>.  </p>
  
  <p>Also the user should be asked to insert the <code>credit card</code> details <code>only once</code> while subscribing 1st time, after that for any upgrade or recurrence he should <code>not</code> be asked to insert the credit card. </p>
  
  <p>All these process should be done on my web-site only, the user should not be redirected to PayPal site. </p>
  
  <p>Anyone knows how to achieve this?</p>