[General] Help recovering voip number

I've had a voip home phone for > 15 years. In November, I learned the service had been transferred out to another provider without my knowledge from PhonePower. Now, PhonePower states I need to get the other provider to give me the acccount information to allow transfer back, or forget it and get a different number. At a loss now on how to get it back. Any help appreciated. TIA