My question is about this sentence:
我が社の商品は値段を上げません。 (wagasha no shouhin wa nedan wo agemasen)
At first I thought there was a typo ("wagasha wa shouhin no nedan wo agemasen" or something like "wagasha no shouhin wa nedan ga agarimasen/ageraremasen"), but I was reassured this is not the case by two 先生 of mine.
That は would actually be a の, but it's changed to は to add emphasis. So it's not a topic-は, it's more a contrastive-は(?)... or so I thought, because I've never heard of an emphatic-は (please don't confuse "focus" (集点) with "emphasis" (強調), which is a different thing).
Moreover, even if the one in the sentence is not a topic-は, I can't have one at all in this sentence (while I can have a topic-は and as much contrastive-は as I want). Specifically I've been told I can't put in wareware wa as a topic: 我々は、我が社の商品は値段を上げません。
However it's grammatically correct to think the subject is "wareware ga"... 我が社の商品は我々が値段を上げません。 ...but I won't ever find a sentence like this.
I've studied this topic (は と が) really hard and never came across something like this. The explanation I've received is seriously lacking: it's more or less what you can expect of a native speaker (who knows what sounds right, but can't tell you why) so I ask you. Is it true that not just が and を can be replaced by は, but also の? Can you give me more examples and help me to reason this out?
Every answer will be very much appreciated