Ok, so my core issue is the tools selection for the job. A spreadsheet is really difficult to manage, especially without correct setup. Having 5 people add to a spreadsheet, without each one of them reading previous issues and marking issues as complete, or marking a complete issue as an incomplete one by the clients, is a mess doing it in a spreadsheet that doesn't have any way of managing it.
If at some points columns, filters and so forth are added, it maybe could get a tiny bit better, but it's still miles away from current ways of doing with that kind of issue management.
I can say, to a good extend, that I have lost more than half a month just answering to issues that are either non-existent or already fixed, but because they were reported many times and/or the client doesn't really understand were/how they were solved they're either still "open" issues or reported again. That's a lot of development time lost in answering and explanations to client questions.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.