Chargify / Wordpress Integration tied to adding/resetting of website tokens upon first and future subscription payments.

This role will require experience with Wordpress/Chargify/PHP/Javascript/MYSQL Our website currently uses a form of payment token that allows users to purchase digital downloads from us. We need to replace this system with a series of subscriptions which will automatically give a user a number of tokens to use every month. Once a month has passed the user will be billed again and, if the payment is successful, the number of tokens reset to its original amount. There needs to be several tiers of subscription and we must be able to customise the following from within wordpress (we would expect to customise the actual Chargify subscriptions from within Chargify only): - Addition of a new subscription - Name - Amount of tokens given each month A user must be able to upgrade / downgrade / cancel their subscription and this must sync with Chargify. A previous company have done some work on this but not managed to fully complete it. Whilst you would be under no obligation to use any of their work, you are free to use any of it you wish if it will help you complete this brief. Following are several examples which might help visualise the required task. Example 1: John signs up to the site on the 20th of January and purchases a monthly subscription for $25 that gives him 30 tokens each month. He uses all of his tokens within a week and is left with 0 tokens. On the 20th of February his credit card is successfully billed for $25 and his account is refilled with 30 tokens. Example 2: John signs up to the site on the 20th of January and purchases a monthly subscription for $25 that gives him 30 tokens each month. He uses 5 of his tokens and has 25 tokens left. On the 20th of February his credit card is successfully billed for $25 and his account is refilled to 30 tokens. Example 3: John signs up to the site on the 20th of January and purchases a monthly subscription for $25 that gives him 30 tokens each month. He uses 5 of his tokens and has 25 tokens left. On the 20th of February we attempt to rebill his credit card but it the transaction is declined or fails. His account is then reverted to the base ‘Free’ level and he is left with 0 tokens.