A/C

They would have to vacuum the system down before it will allow freon to go in, you know if they did?

Definetely go to another shop. If the system wasnt vacuumed properly then moisture and other particles have gotten into the system most likely plugging it somewhere down the line. Also a certified tech would know that you cannot significantly put a charge in the system if the vehicle and compressor are not running. A certified technician will determine whats wrong and if there is a blockage in the system and if thats the case you will likely need to replace the expansion valve, filter drier, flush the refrigerant lines and pumpdown using the vac purger and properly recharge after all necessary repairs. Hold onto your receipt from the shop that had worked on your system. If another shop finds that the work wasnt done correctly and has led to other problems then you can hold the shop accountable for their mistakes and have them reimburse you for the charges of the additional work you had to pay for that was a result of their mistake. I'd even bet that whoever the technician was that originally did the replacement was not even certified to do the work. You must have state certification and certification from the EPA to make those kinds of repairs on any type of hvac systems.