Paypal expert with asp.net / vb.net knowledge

hi, I am looking for a paypal expert for the asp.net/vb.net platform for basic tasks for subscriptions. I have already implemented the subscription (monthly yearly) What I need is : - The user should have a button to downgrade or upgrade (= changing the actual subscription ) – there we have at the moment the problem “20% limit on increases to subscriptions.” – as per telephone with paypal this is only possible in USA – not in Europe ??? – so we have to cancel it and make a new one, but for the user it should be only one easy button! - so if we change the subscitpion – cancel it before and make a new one (unsubscribe) Up to know I was using the methods on this site: [login to view URL] So what I need is: - Cancel subscription per code/api - Make new one (have already, but maybe wrong for cancellation) - the notify url is my part and not part of this project - code must be in vb.net At the moment I am using the sandbox and a testserver. Please give me some links where you have already implemented similar solutions and as I know many bidder do not read until the end of a description please tell me at first what is the sum of 2+2 :-)