HELP! Employee Size Range Chart/Table

I'm not sure what the best practice for this kind of thing is. I've tried a few things and have gotten close, but I don't know where to go from here. So I have this table that contains Company ID, Employee ID's for that company, and their services offered:

What I am trying to achieve is setting up a graph (pie chart) that shows how many companies have 0-25 employees, 26-50 employees etc. etc. REGARDLESS of how many services are offered so nothing is double or triple counted on companies that have more than one service. When building this I sometimes will get something like a company with 24 employees will be placed in the wrong category, like the 26-50 employee range. Or sometimes a company won't be listed in any category even though it has employees. On the pie chart I'm simply trying to display the distinct count of Company ID's by their perspective range for example:

556 companies with 0-25 employees

438 companies with 26-50 employees

213 companies with 51-100 employees

etc.

I then try to build out individual tables of these ranges with the distinct count on the Company ID column and a total sum count on the Employee ID Column, but sometimes the totals for company ID do not match what's on my pie chart when I expect them to. What is the best way to set something like this up?