weight bearing beam compromised
hi there, i am having a serious issue now... i bought a 82 year old tudor house, beautiful home with very sound structure. i had several contractors in yesterday to install recessed lights in the living room as it is a bit dark and my kids are scared of that room. they tried to fish a wire down to the basement of which the ceiling is all covered by plaster. They broke a small area (3*3) on the basement celing to exposed wood and started drilling upwards thru what they thought was subfloor. They used a at least foot long drill bit. Drilled 4 holes, couldn't get thru. Went upstairs, started drilling downward from inside of a wall cavitity and again after 3 or 4 holes, the drill bit didn't show up on the other side even though it was totally in the wood. They told me that the wood piece was too thick and was looking for even longer bit. i said wait and went down stairs and from another session of the basement where i can see the framing a bit, i found out these are 2*10 or 2*16s (two together) and weight bearing as other joists are attached to it 1 foot apart when this beam is at least 5 ft apart from another weight bearing beam. Now I am really scared. Apparently 7 or 8 holes have been drilled on it in a small area and i'd imagine they totally destroyed the integrity of this beam. Right now, it don't see any issue yet. But i am afraid that it might give after we move in with heavy furniture. My question is:
1. what can i do to fix it (adding another piece of 2*10 or 2*16 next to the two and nail them together)? it is pretty hard as the ceiling is all plastered.
2. is there any kind of reparing thing I can inject into the holes from those i can see in the basement ceiling (the wall upstairs is already patched) and then hardes into a strong structure that would fill the holes and also provide structural support.
2. how do i deal with the contractors. they insisted it would not cause any damages. can i sue them?