Equipment Protection, Monitoring Electricity

Your amp is on one 'leg' of the 120v/0v/120v American ? system
So one leg can swing down and you have a 'brownout' which is low voltage. hard on transformers..
The opposite is high voltage, and it can be 127volts and zero issues. When it get upwards of 130volts plus then you might start having some issues.

One solution if this is a regular issue is to have a voltage regulator.
I had a Monster AVS2000 years ago, but felt I really did not need it.
I currently use a Frumar REF 20i which solves undervoltage with a stiffening capacitor. And has an overvoltage shutdown.

I would say find a surge protector which shuts down under dangerous overvoltage or undervoltage conditions.
Computer ones often have such protection.
It would be advertised as having such protection.

I'm no electrician, and there are some very knowledgeable people on here who can really explain it, but let me understand the facts: a transformer of the utility company blew? And that is what you think fried your amp? Very possible. I think that's one reason why people have surge protectors, but I'm not sure a dinky little consumer appliance type surge protector could handle that. If I have the facts right, I would assume that the power company has now replaced the faulty equipment on their end. But, you don't have any idea what may be wrong in your apartment building. I would assume that the power company has responsbility up to the meter, and after that, if there is faulty equipment, or stuff that got fried when the transformer blew, it is the landlord's responsibility, which as you said, means nothing.
Perhaps you can: call the power company and ask them if a field person could come and inspect the line up to your building and take some measurements; maybe if the power company person is righteous they would help you out and check the power in your ap't- and big maybe, give you a clue whether your building is in violation of code or there is some obvious problem resulting from the transformer issue; find a local electician friend or pay one who would be willing to take a look at the current in your apt- it is pretty simple to measure with a meter, but you sound like you don't have a clue, and inconsistencies in power may be intermittent- usually worse during the day because of demand.... but in an apt, with everybody home at night, you may be having more issues then.
The other thing to explore by some searches here, and advice from people smarter than me, is whether any of the regeneration devices will work if the current going into them is really inconsistent. i don't know- the whole point is that they 'regenerate' the power so it's cleaner, but you'll probably have to pay a few thousand bucks for one and i'm not sure it will work.

Thanks for the advice. The first thing to do is to call the electric company.

Ok, the electric company said that they show good electricity reading to the meter. I need to find a meter and figure out how to take the reading. Elizabeth, Whart, anyone, any more suggestions, where to find a meter, etc...?

This comment may not be welcome. But i would also say your fears are too much.
Yeah you may have had a problem, and it might have been connected to something else which happened.
I do not think you should get worried about it though.
(naturally when something else happens, you can blame me)
Anyway, I would say stop worrying about it.
Stuff happens. Worrying about it does little good.
It may have been just a coincidence anyway.
Personally I would just go forward and figure all will be OK.
Natually if anything else goes soon enough, THEN yeah maybe something needs to be done.
But i bet it will all be OK.

In 47 years i have had two amps go out. One with smoke, and one just a loud POP! and a bad smell.
That is the way stuff happens.
So IMO: Why worry, be happy.
Yeah it is not what you want to hear, but it is my best suggestion.
Otherwise you could also buy an isolation transformer.