why my ac blows hot air?

What is your question?

i had nearly $700 worth of work done in december. then i took it back in may and was told i needed another $1800 worth of ac work that needed to be done because of freon leak. freon was added that day. i did not do work requested and yesterday my ac stop blowing cold air. it took 2 days for it to go from cold to completly hot. i checked coolant and it was full matter of fact it had more than it needed. i am writing you to see if this situation needs for me to get the attention of corporate nissan? can you advise? stress'in bad!