Visual Voicemail as SMS?

First post here, though I've been lurking the forums ever since I got my phone since the most helpful Android advice seems to come from here.

Starting a few weeks ago, I began to get messages from 8737 and 9016 mostly full of what appeared to me as junk code, sometimes as many as four a day. Browsing other complaints of the same issue informed me that these are voicemail alerts that I shouldn't be getting, but my problem is this: how do I stop getting them?

Most of the advice I've found involves instructions for third party SMS apps and I've never installed one. I've tried clearing all the stored info for my voicemail, recording a short message and sending it to activate@vm.sprint.com which some people said would reactivate the visual voicemail service but unfortunately that doesn't work for me either.

It does seem to be a Sprint issue, but Sprint's advice is to do a factory reset which quite a few people have said didn't work for them and frankly I'd rather not have to customize my phone from scratch all over again. On top of that, my phone service is actually with Credo who just uses Sprint's network, so Sprint doesn't recognize me as a customer.

I'm at my wits end! Help?

 

Just popping back in with a successful update!

I spent a while on the phone with Credo and they were incredibly helpful. The basic things we tried didn't work, and strangely enough the voicemail to text trial wasn't even activated. In the end, we did have to resort to a factory reset (not nearly as traumatic as I expected, as they helped me back up my contacts and showed me how to find all my apps) and it worked!

We still have no idea what happened, but I'm finally getting my voicemails again and it's a huge relief. I just wanted to leave this here so anyone else with a similar problem can see my solution.