There's a poem called "The Chaos" by Gerard Nolst Trenité that demonstrates the irregularities of English spelling. I don't wish to post it here due to its length, but it's worth checking out.
Well, I'll post the first few verses:
Dearest creature in creation
Studying English pronunciation,
I will teach you in my verse
Sounds like corpse, corps, horse and worse.
I will keep you, Susy, busy,
Make your head with heat grow dizzy;
Tear in eye, your dress you'll tear;
Queer, fair seer, hear my prayer.
Anyone interested can find the full poem here: http://ncf.idallen.com/english.html
You've introduced a rule from around 1850 - a rule that never really was a rule, where the exceptions seemed to outnumber the instances where the rule applied.
Some people wisely refer to the "rule?" as a guideline.
Here is a simple, but quite thorough explanation of the ie/ei/c/plus other exceptions guideline:
I remember this QI episode about the "I Before E Except After C" rule:
That's exactly what I think about the spelling rules in English. "But why do we write it this way then?" -- ¯\_(ツ)_/¯