Block his calls, but not texts?

I want to block a number from calling, but still want to be able to receive their texts. "Do not disturb" feature doesn't work for me as it tells people I'm on another call instead of sending them to voicemail.
Are there any iPhone apps that block numbers?

I spilt milk in my iPhone?

I spilt milk on the speaker at the bottom. Now it's crackly and quiet. I just got the phone yester and spilt milk in it last night. The sticker is not red. Do you think I could take it back to T-Mobile and just say that it came this way? Or is there a way to fix this?

HALPPP my iPhone got hacked? I think?

Long story short, I left my iphone at an exes house and she messed with it for sure. So I get it back today and there's no passcode and the background is a generic one, I think the one that is initially on it when you get the iPhone. So I don't know what this crazy waste of breath did but my phone ain't the same. I still have all my apps and contacts but i don't know what she did could she have hacked it somehow? She's a stalker ex so I wouldn't put anything past her.

Has My Number Been Blocked by an iPhone?

I've called the number and it rings once and diverts to voicemail - I know this is the most obvious sign of being blocked so I called BACK. This time I got a different result, it kept ringing as though it normally would like the call had connected.

I tried this a few weeks ago and the exact same thing happened - called once and it went straight to voicemail, called again and it kept ringing as if connected.

Does this mean I'm blocked? I've heard that if you have, it will ALWAYS go straight to voicemail every time you call. But I'm getting different results each time, is this normal for being blocked or not since it rings?