Brown and clear spots or blisters on Phal leaves?!

[TheEarnestOrchid]

Hello everyone, I seem to be having a sudden problem with the leaves of one of my phals...

To give a brief overview of it's history: I was given this phal as a present about two months ago (purchased from a grocery-store), and other than the roots (starting to rot in old sphagnum) it looked extremely healthy. It was in bloom, then due to an accident the spikes were broken, I put cinnamon on the cuts, one of the spikes started to regrow and now has several buds and everything seemed fine.

However = two days ago, what looked like a clear halo appeared on one of the leaves. By the next day, this had developed into a raised brown blister - raised on both sides of the leaf - surrounded by an indented circle...

Then today (3rd day), when I looked at it again, I now noticed a second larger watery circle (with a small brown dot in the centre??) higher up on the same leaf...When I looked more closely, I also noticed a similar patch on the top of a second leaf further down.......

I will try to attach photos - please bear with me!

I think this is some sort of infection, given how suddenly it has occurred/quickly it is progressing, and plan to amputate the leaf/sections :S

All help is greatly appreciated! I hope it's not too late to save this phal...