The fix depends on how the calls got blocked in the first place, and there are two separate places the block could be sitting.
If you blocked the calls on your personal phone, through your carrier's call blocking feature, a third party app, or your phone's built-in blocking settings, you can unblock them directly on your end without involving the facility at all. Go into your phone settings or call blocking app, find the number associated with the facility's phone carrier, and remove the block. The calls should come through immediately once that is cleared.
If the block is on the facility's side, meaning the number was flagged or restricted within the prison phone carrier's system, that is a different process. In that case you would need to contact the phone carrier directly, whether that is Securus, GTL, IC Solutions, or whoever services that facility, and ask them to remove the restriction on your number. You can also contact the facility and ask to speak with the case manager or counselor overseeing your boyfriend's unit. They can look into the status of the phone account and help get the line cleared from the institutional side.
The quickest path is to try your own phone settings first since that is entirely within your control. If calls still do not come through after clearing any blocks on your end, then move to contacting the carrier or the facility.
If you are using an InmateAid number and the issue is on that end, email aid@inmateaid.com and the team can look into it right away.