Why doesn't Boost Mobile Blackberry 9670 ring on my end?

I bought this phone used because I really like this phone. When someone calls my phone it rings 2-3 times on their end then goes to voicemail. I get a voicemail alert so I know someone called. Phone never rings on my end. Call forwarding is turned off. I have followed suggestions from Boost Mobile tech support but issue is still not resolved. I'm hoping someone here can tell me if this issue can be resolved or if I should toss this phone & get another one. Thanks.

Go to the Call Settings then select Call Blocking and check the status for the Call Blocking.