Since I have not heard back from you I am going to try and answer your question and presume certain facts. Note if the facts are actually different that would potentially change my answer so reply back and let me know if I presume something wrong. Based on the level of detail you provided above I am going to presume that you did not trip over anything on the floor or slip on anything causing your fall. I am also going to presume that the store employees had no previous knowledge of your medical issue and that you simply collapsed after having to stand for to long of a period. Again let me know if any of this is incorrect. While I completely understand how upset I would be if this happened, I am unaware of any civil claim you could make against the store related to either the rudeness of the employees and/or you collapsing resulting in the call of an ambulance. I know this is probably not what you wanted to hear and I would ask that you not shoot the messenger. I have an ethical obligation to provide you accurate information to the best of my ability. The typical claims you see are slip & fall and that is related to the fact that the store has a Duty to an invitee to take reasonable efforts to remove potential safety risk to its patrons. Since they have a Legal Duty then once they breach that if the party can prove they were damaged the party has a basis for a civil lawsuit based on negligence.
In this case, I don't see that the store intentionally or unintentionally breached a legal duty to you. If you were disabled and they failed to make reasonable accommodations then the store might have violated a Federal or State policy related to necessary accommodations for those that are disabled. In that case it is generally not an individual parties claim, but more likely a claim brought by a state or federal agency related to a complaint and potential fines or penalties to bring about future compliance.
Again, I am sorry as this is probably not the news you wanted to hear. That does not mean that you don't have recourse. While you may not have a viable civil claim that is not to say that you can't contact upper management and make them aware of how you were treated. I have found personally that most businesses take a legitimate complaint serious when a consumer takes the time to write a letter and send it not only to the store manager, but also to his boss and perhaps the owner if it is not as huge as say Walmart.
You can likely get this information by calling and asking for the store manager's name. While talking to that person, ask for their name, and then ask for who the local manager reports to. By asking the person you talk to for their name they will feel more compelled to give you accurate information so that they are not named in some letter. You could also ask for a corporate customer service manager or when you find out who the store manager reports to you can ask for that person's name and address. You can also find alot of this by searching on the internet.
It would be fair to threaten to make this information public such as facebook or other means (don't say anything that is untrue as you could be sued for libel if the information is defamatory and untrue. Truth is an absolute defense to any defamation suit so if you restate the facts accurately you can not be held liable. Do note that anyone can sue anyone and someone might threaten to sue and you might have to defend a case in court, but truth is a defense.
I would not go the facebook route unless you get no response from the store. When you write them you need to have some ideal as to what you expect them to do. It may be that you expect the manager and any participating employees to be disciplined and you want an apology from the store? You could always ask for a certain limited sum of money related to the inconvenience this caused you. By that I am only thinking of $50-$100 store credit you can come up with what ever you feel right about. If you go back or send someone back you might look to see if they have video cameras around the whole front area. I say this because an upper management person might actually review the video if you provide the date and approximate time of the event just to review how his employees treated you?
Again I wish I had different news to offer.
I want to thank you in advance for giving me a positive rating for my answer or if for some reason you can't please reply and let me clarify anything as that is the only way I am compensated for the time I spend answering your question. Even after rating me you can always reply to my answer and ask follow up questions or get more clarification.