Firestone Complete Auto Care review: Poor brakes installment

Good afternoon, My name is Beverly Tripline. My compliant is this year I had purchased brand new back brakes and had them installed in my car. I have a 2015 Nissan Senta SV. During the Covid-19, I have to work from home, therefore, I didn't drive my car often. However, after about a month or two, I noticed that when I had driven the car, my back brakes were screeching, so I took it back to Firestone. I was informed that the brakes probably had gotten some water in the line from the rain, or the car sat too long. Also, I was told that the brakes were okay to drive on, and to continue to drive until the dampness of moisture is depleted. Currently, I am still having the same problems, I really believe that the car brakes weren't checked properly. In addition, I am going to take the car to the dealership to find out the problem. My concern is that paid monies for lifetime brakes that are still screeching every time I would back up or parking the car. I am not comfortable in hearing this sound, nor do I want to have any bad accidents. I would like to be safe when driving. It would greatly appreciated if this problems could be solved due to safety purposes. I can be reached at [protected] or [protected], or email at [protected]@yahoo.com Thanks in Advance, Beverly Tripline