Had a shop change everything on the A/C system and it still didn't blow cold

"Everything"?! That's quite highly unlikely. In the heater box, perhaps. But what about everything else? And what testing was performed? You need proper testing performed by a technician skilled and capable of handling refrigerants legally. You could have an electrical concern, a refrigerant system concern, a climate control concern, a cooling system concern, or otherwise -- hands on testing is needed. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops