Alright so my AC stopped working (never happened in the 3 years of ownership) and had a blinking light when I pressed the AC button and so I took it to the Mercedes dealership and they said the a/c system was low on refrigerant by monitoring the actual values, along checking the pressure gauges.
There was dye in the system (not done by me). They could pick up dye on the high-pressure a/c line from the compressor and the condenser. They were also able to pick up the leak with a refrigerant sniffer from this same high-pressure line.
They said it has a few leaks and so they removed the refrigerant and said that the lines and O rings will need to be replaced ($700 fix)

I took it to Volkswagen since the Merc dealership was far/busy and I am busy as well. They did a leak/vacuum tests and said there were no AC Leaks and so they refilled the refrigerant with an improper amount of 630g and said that the AC was working again and come get the car.
I showed up and tried the AC and it was not working and an error code B1191 (I think expanded to B119184) - refrigerant level outside permissible range was there. They said the issue was with a faulty sensor giving improper reading and they don't have the expertise to deal with that but I looked online and found that for my 2014 Mercedes C350 was only supposed to have 590g of refrigerant put into it.

I asked if they could inspect a sample of the refrigerant when they take it out for metal flakes indicating damage in the compressor but they said they cannot do that, they did take out all the refrigerant, performed another leak test, and put back 590g and cleared the code and it is still not working even though they said it originally did after their "repair".
I'd figure that the sensor had a fail safe and triggered that code when the AC was over filled but it is still showing up after the correct amount of refrigerant and 2 tests for vacuum leaks.

I am wondering now if due to the overcharge they may have damaged the AC compressor what should I do? Is there something else that could be wrong?

 

I would take the car to a local AC specialist shop. The AC systems in most vehicles are very similar and have common issues. An AC shop sees many, many more AC systems than either the MB or the VW dealerships and can recognize problems much, much quicker. If you know any car guys, ask them who they would recommend.