AC not cooling enough how to fix

.
We received a phone call around 2pm on a Friday in Singapore. A lady, Alice, was complaining about her aircon was not cooling, even she set it at 16 degree Celsius for a while. She also said that the aircon are cleaned few days ago. We were concerned and quickly asked if it was cleaned by our company, but she said ‘No’. We were relieved for a moment, because we have not had a complaint for many years.
.
2 things that we have done right to reduce complaint. Firstly, we ensure our customer satisfaction. We function checked the aircon with our customer after every services. This is to let the customer witnessed that everything is working properly before we leave the location. Secondly, we provide value added service to our customers. We did a basic check on the whole aircon system in the beginning. This avoids potential failure in future. We will consult the findings to our customer before we start and let them decide if we can fixed it for them.
.
Alice wants her aircon checked before Monday and we are fully booked for the weekends. She also had the aircon compressor locked in another room. These gave a bit of a challenge as it is already Friday afternoon. I instantly called our Operation Team Leader, Ed. He said he was still working on an aircon repair around town area and would not be free until 7pm. I checked back with Alice if it is possible at 7.30pm since her office was at Macpherson. She said Ok and she will wait.
.
Ed arrived on time and begin to troubleshoot the aircon problem. The filters was still cleaned, but the coil fin were cloaked with many dirt. He also found out that the refrigerant or air con gas pressure were out of range. Ed offered Alice the repair cost of an aircon chemical wash with air con recharge to fix the problem. She agreed and Ed began to wash.
.
When the aircon blew some cold fresh air into the office, Alice was delighted. The whole area was filled with refreshing cool air again. Ed once again function tested the aircon right in front of Alice after the aircon chemical cleaning service. This was to ensure that she was happy before we left.
.
Information collected from Alice, Macpherson Singapore.