Just because something is false doesn't mean it's a "fallacy" - at least in a philosophical context. That word is reserved in philosophy, generally speaking, to mean logic that by virtue of it's deceptiveness is tragically bad.
In this case - the "Stupid Assumption" - I would say this could possibly be a fallacy called "begging the question," which essentially means:
"...begging the question (petitio principii) can occur in a number of ways. One of them is when the proposition one is trying to establish is unwittingly assumed."
Or, simply by saying "This company is stupid" you are actually just stating the thing that you are trying to prove. It's circular reasoning. The other propositions stated (such as "they blocked my a TV show") don't lead to a conclusion of "this company is stupid" - that has to be assumed for the conversation to even make sense.
People are casually, conversationally, question-beggers all the time and it's not normally a problem. They're either not saying what they actually mean (I hate this company for preventing me from watching what i want) or the remaining logic is assumed / implied / obvious.
So, that's why I include the caveat of tragically bad in the context of philosophy. There's enough implied in the comment for you to assume it's someone's opinion. It's under circumstances where things are stated as facts that it becomes truly messy and where I feel like the term "fallacy" is appropriate.
An example:
"I should get paid for answering your question on philosophy stack exchange because people who are helpful deserve compensation."
Sneaky, factually stated, circular reasoning - completely inaccurate. Fallacies in philosophy are wolves in sheep's clothing. If werewe're too liberal with the term's usage we run the risk of conversationally pedantic.
Hope this helps. Happy hunting.