Nothing annoys me more than muppets that just don't understand RNG. Your ToC are working right. Probability does not stack. If you have a 20% chance for ToC to proc, that means you have an 80% chance of failure, each and every time. Repeating it does not reduce this 80%!! It's quite possible, though not very likely to run those odds a hundred times and never have that 20% proc! That does not mean ToC is not working. It's probability in effect. It's quite possible some lucky chap just got 4 in a row. Stop complaining that this or that method did not work with ToC and educate yourselves on how probability actually works.!!!