Dacia Lodgy air conditioning suddenly warm?

Recently, our Dacia Lodgy's air conditioning system was repaired. The air coming out was quite cold. My father suddenly commented that it was supposedly sometimes cold and sometimes a bit warmer. He then took it back to the workshop and said that the air conditioning fluid needed to be topped up or replaced. When I drove the car to test everything, I noticed that only warm air was coming out. No cold air at all. I remember that the workshop connected red and blue cables from a device to the car. What do you think? What could be wrong? Did they perhaps forget to top up the coolant? They're planning to drive the car to Turkey in two days… I'll be taking it to the workshop for the third time tomorrow…