I use voip and voip only, no real cell service so maybe I can help. First option is an app called sipdroid in the market. If you have a google voice account and already have it setup with the official google voice app in android, then the first time you open sipdroid it will have a button at the bottom saying something like "link pbxes account with google voice" if you do that, it will make you an account @ pbxes.org, link google voice to it and save it in sipdroid. You can then make totally free voip calls and receive calls with your google voice account. Doing that in sipdroid is the only way I think there is to get a gv linked to pbxes for calls with a free pbxes account. But there's a 2000 minute per month allowancwe and pbxes enforces that pretty strictly, I have got a few accounts disabled and some completely removed for going over. Another option is grooveip(another market app) its not free, like 3.99 I think, it does the same thing as I said above and uses your google voice number for calls but I don't think there is a limit to usage like the pbxes option I first mentioned. And its a one time fee for the app, not a monthly fee. If you go this route, you only need the grooveip app and a gv account, no other apps or voip accounts are needed. Both options I mentioned above have worked great for me. Need anymore help or advice, just let me know!
Forgot to mention, google voice is free and u get one number assigned to youj for free and it does sms text messages with tthe web browser or the gv app. And you can text from the pc or basically any device with a web browser. No picture or multimedia messaging is supported with gv yet tho.
I have tried ipgroove because it sounds amazing, I bought it and it didnt work. Support was quick to work with me, and they said it wont work on my droid x2 yet. I have used gv by itself, but it wasnt enough because I need sms as well. I am trying line2 for 7 days free, it is 10$ a month after that and it is amazing, but expensive compared to ipgroove.
That sucks grooveip didnt work for ya, works great for me. I hope you were able to get a refund. Before i bought the app or b4 i buy any apps, i download them first from a warez site for free and if they work how i expected, i buy them.