In the beginning, MTC's total supply was 1 billion and the current total supply is 783,285,021 MTC according to CMC.
This is the contract address for the burned MTC 0x34afa7ff9a8eb4d8e61145ca81e2d0dab7b03662, the amount is 216,714,979 MTC
1,000,000,000 MTC - 216,714,979 MTC = 783,285,021 MTC
So it is for sure that there is no hunky punky with the supply because everything is transparent. However, I'm not sure yet about the marketcap what you've mentioned. I hope you will get an answer from their TG.
This means that the only way that the actual supply of tokens could have changed is that they released tokens which were locked for the team or partners.
The icobench page states that there was 350'000 tokens initially for sale. According to your math, it would mean that currently there is 2,23 times more tokens than initially. Thus the market cap at constant price now and then should be also 2,23 bigger.
But when I take a look at coinmarketcap data, i get this:
May 12 2018
Marketcap:3,235 million
price: 0.0174
Jue 27 2019
Marketcap 12 million
Price 0.01737
Market cap has increases 3,7 times. So it does not fit the supply calculation increase.
The Telegeram is useless, I tried to bring this matter to attention several times. Only answer I get is from people who are calling for 10$ price and does not care about anything.
Maybe i should try to tweet them.