aspx or php API integration server to server Mysql / SOAP

I have a bills payment system, and the service provider has provided me an existing website link for this and they are using ASPX but my wordpress is hosted using Linux, can i use my API tech details on my existing host i want it to be set up in my own domain so what i need is a server to server setup for API. I want to modify the existing website for us with additional features: I can send you the site link with username and password to check the existing site just private message me. Features i need is: Bills payment portal Admin side: a. Branch Management 1. Create branches 2. Create users 3. Create balance / Limit b. Admin Tool Box 1. Admin report detail 2. Totals per branch 3. Totals per users 4. Balance inquiry c. Create custom payment system 1. Create bills to accept 2. Create fees for users 3 Create commissions for admin 4. Print payments 5. Totals new payment system d. Deposit information User side: 1. E-Load 2. Prepaid Cards 3. Electronic Cash 4. Bills Payment 5. Customs Bills Payment 6. Reports 7. Online Help 8. Control Panel 9. Balance Inquiry * for the custom payment system, i want to be able to upload a logo, create fees EX: Php 5 pesos per transaction, with the following details: Account Name: Account Number: Reference Number: (optional) Total amount to be paid: * There should also be and export options for the total amount paid with complete details * There should be a print options for complete details and amount paid * The custom bills payment balance and transactions are not part of the system, this should have its own transactions search, total amount paid and total amount of fees * There should be a balance setup per branch so that they will not be able to transact once their balance is depleted. * I want balance email notification once the balance is already low in funds for admin and users Right now each bills has a corresponding amount of fees deducted in the total funds for each transaction using the link provided by the service provider, I want to add an additional 50 centavos commissions deducted and placed in the admin commission * There should be a balance inquiry with total amount of our commissions for admin.