I Cannot Get One Of Your Mci Wireless Phone Numbers To Ring Through.

The call will not go through and instead, pings back to the main screen. The same thing happens when the other party tries to call me. I have Safelink Wireless service as my carrier but I've never had any problems calling anyone else - on landline or other phone numbers with other carriers. I've contacted my service carrier - Safelink - and they've already checked my service and phone and have told me there are no problems found. I also just called your Tech Support and they said the same thing but when I asked why, then, can't me and my other party get our calls to go through, your Tech Support transferred me to my carrier when I already told him that I had already checked with Safelink. . Can you please assist me with this?