Recently canceled Google Voice and now calls to my ATT number say it's disconnected?

AT&T voicemail forwards all missed calls to a secondary number with AT&T. That voicemail box number is what’s missing from your phone. You will have to call AT&T and have them set up your voicemail box all over again.  

Sounds like your GV number is still being used for voicemail. You need to update your voicemail number.

It does seem that way, but how does one update the voicemail number? I have an iphone 6 and have looked all over it for that option.

see if it's forwarded. Since this is on an iphone it's not a home phone issue so I'm moving to wireless. 

I used GVoice number with my ATT Apple mobile phone (Dual SIM card) -  I’ve visited the ATT store to get a new SIM card but that did not work

I deleted my GVoice but when people call my ATT number they get the message “We’re sorry - the Google Voice number has been forwarded too many times”

Please help as I have not been able to receive calls for a few months 

please help

Sounds like you need to contact Google voice 

@Jhtate 

If you were having all of your AT&T phone calls automatically forwarded to your Google Voice number, now they go nowhere.  

You need to contact AT&T and make sure that your voicemail is set up, and that your calls are not being forwarded anywhere else.

This is the same as information that is in the solution post, for last year. 

Try Reset Network Settings.

To see where your calls are forwarding now, dial *#61# 

Got it thanks