Repairs caused other problems: horn doesn't work, headlights don't blink with lock remote use

Maintenance/Repairs
1

Recently I had two different repairs done at two different shops about a day or two apart:

  1. no air conditioning: The bashed-in front bumper was replaced, the dented AC condenser was replaced, and voila: for $600 I now have air conditioning.
  2. driver door lock wouldn’t unlock with remote: The previous make-shift repair was replaced with proper motor, and voila: the remote works on the lock.

Immediately afterward there there were two new issues that emerged which I think are very likely related to the repairs:

  1. horn does not work
    The guy who did the air-conditioning repair thought maybe he hadn’t connected the horn wire when he replaced the bumper, so he removed the bumper (at no cost) and noticed the horn wire was not connected and was missing the necessary part to connect it. I figure this was caused when he yanked off the bumper. He can get the part and make the repair. I think he should do it for no cost, since the horn was working fine when I brought it in. The shop wants to charge me one hour labor @$100 plus the $35 part. I’ve asked that he call me so I can discuss this. He hasn’t called. I have an appointment in two days. Meanwhile they’ve ordered the part. QUESTION: Should I be charged for this? Maybe I should agree to pay for the part? or pay half the entire cost?

  2. headlights don’t blink when I use the remote
    It seems to me this problem could have been caused at either shop: the first because they were working around the headlights with the bumper, etc. or by the second which was working directly with the door lock.
    QUESTION: Which repair is more likely the cause? The first says, oh, no, it couldn’t be from the air-conditioning/condenser/bumper repair. The second said they don’t think they did it, but they are willing to look at it.

2

What car, model, year, and how many miles?

3

What make, model, year, mileage, and a few more details on some of the damages on the car would be helpful. Also, was the car like this when you bought it? There is a lot of unknowns on this one.