After taking car to the dealer for the HVAC blower not working, many issues have turned up costing a great deal of money?

My blower stopped working. Heat worked before the blower went out. All the knobs except the blower speed select worked properly. Toyota fixed the blower and then the knobs to the mode and A/C and heat would not turn properly so the heat wouldn't come on. Not sure about A/C because you couldn't get the knob to select cold air. These worked properly before Toyota went in to change the "heater relay in the kick panel and installed a new blower switch" so the blower worked now for $640.00 but the heat and knobs/dials that worked before it went in, didn't anymore. They were also supposed to check the alternator beyond the multipoint inspection (which they charged me $60.00 for) because it was towed there because the car wouldn't hold a charge. The blower switch and relay was a 3 hour labor charge for my heat to stop working and my knobs to be messed up, the alternator passed whatever test they did and not even a week later and only 127 miles, the car loses power again and needs a tow to Toyota. They say they couldn't have known that was a problem because everything was fine before and that I need a new alternator, battery and driver belt. That was fixed for $900.00. When I asked them to look at the knobs and the fact that the heat worked before they got it in the first place, they said, now it's the entire "blower assembly box and all of what goes with it for the entire part at just under $2,400.00 not including up to 12 hours of labor which they were going to be so kind as to knock down from $1,914.00 to $1,140.00.
My problem is this: the heat and the dials for the mode (defrost/feet/dash/face) and the Heat-A/C were only messed up after they went in (for 3 hours to change the blower switch (a 20 minute tops job if you include the relay behind the kick plate). I'm assuming something they did while they were in there caused that problem. They had the car for 6 days, fixed the blower, messed up my A/C-heat and mode dials, checked the alternator that was good and 6 days later that and the battery and the belt are bad which costs $900.00. $1,500.00 in when I take it back to say the knobs are messed up and the heat doesn't work, they tell me its going to be another $4,000.00 (at least to give me heat and A/C in my car) which I had before I took it there in the first place. This is actually my brothers car who has a disability. I manage things like this for him from another state 9 hours away. I feel like they are taking advantage of the situation as well not thoroughly checking the vehicle and not taking responsibility for what ended up broke after they fixed the blower. I'm a woman trying to handle my disabled brothers business and I just feel like there is something messed up here.