How to achieve webservice testing automation through programming/coding

I know these questions have been asked many times , i am still looking for an answer that satisfies my question. please have a look at below points what i am looking for:

1) first thing , How to achieve that through programming. for web automation i am using specflow C#. do i need to create unit tests for the web service testing ? what can be done through programming ? soapUi is ruled out as its already used by manual testers. 2)are there any available frameworks for these ? 3)please give me links and examples supporting them.

I know its a broad question. but i do need some help from everyone so that i start in the right direction on API testing.