C# plugin for "Global Payments Inc" payment-gateway

We created the Global payments plugin in C# using the "webservice" method and its complete but needs debuggin and our programmer had to leave. To accelerate the process we can offer the complete source code for the project. It is complete and sends payment requests to the gateway but we get back error "do not use special characters" from the gateway service and we don't have the current programmer to debug. We need a new function to this webservice plugin which is STORE THE CLIENT PAYMENT INFORMATION IN OUR DATABASE. So you need to cyptograph credit card information, store it with a key that we will generate and then be able to restore the information to send the the gateway for future payments (similar to recurring payment). 1 - in 3 days for working beta without saving the client information (name credit card number) etc. 2 - then after that the rest for the cryptography and saving and restoring client information.