Jazz, your posts hit a note for me.
I have just concluded a month-long fight with my electricity supplier - they screwed up my bill - wrong rates, then doubled down and double-screwed it up... It's not funny - It was over $1,000 equivalent.

...then they managed to get it right...after I worked back through their bills in my own time...and explained very carefully why they had to undo the 'correction' they made, and fix it properly...

After they fixed it to my satisfaction, it was OK for four whole hours.. until the system (or someone!) put the wrong values together again...

then the person dealing with it went off sick...

and finally today.. it all seems correct.
I'm in credit!

But - the inability to solve problems, even when I am telling them the answer, is scary.

Inexperienced staff, brain damage, sickness/absenteeism, who knows... I think all of the above played a part in my problems.