Hi guys can somebody please give me some advise;

I am working for a small business for over 6 years and last week i had an injury at work (Was not my fault ).I fell very hard on stones with both of my knee,So hard that it took my breath away.I was bruised and very sore but still went to work on Friday . Whole weekend i was resting my legs with icepacks on it .Sunday night i let my boss know that iam going to stay at home as i can not walk due to the injury.I even send her pictures of my legs and she didn't respond. Tuesday i went to work and immediately i was told i could've come to work and sat on a chair (but i am on my feet the whole day so that would have been inpossible) and if i want to go look for a different job she wont mind and even give me off that day just because i stayed at home Monday .
I was in so much pain Tuesday that i cried but still did i try to tough it out ,But at lunch time i couldn't anymore and asked her if i can go to a doctor as iam really in pain ...She told me "It is just bruises and it will heal and she works when she has pain and maybe she is more driven and more hard working than me"So i went to the doctor Wednesday as that was the only doctor i could've gone to as my boss only gave me R300 cash to go to doctor and the doctor bill was R380.(The doctor not impressed as i needed to come earlier )

So the doctor booked me off from the 16th-21 and said i need to get a X-Ray ASAP of my one leg as she think i fractured my patella. So i whatsupp my boss and send her the Doctors Letter and told her i need to get xrays and it will cost R850 and does she have compensation fund and she just ignored me .Next day a whatsupp her again to ask and eventually she said NO she doesn't have such insurance and She Doesn't need to have it as she only employee's 2 people and i must go to a state hospital (Problem is you pay at a Government hospital unless you are unemployed ).
Well i went to the nearest Government hospital in my area for the X-Ray and it cost me R350.
Well i went back to the doctor Monday
and the results showed nothing broken but she refered me to a specialist and i must get a MRI aswell as Phisio .Doctor Suspects i could have hurt my ligaments in both knees but cant say forsure ..
I am now on meds ,Rest(Booked off from the 22 -6 Sep) and must wear a strap on knee brace on both legs .And cant walk probably or stand without holding on to something.
My boss told me when i Told her i think its unfair for me to pay the medical cost as it happend at work and she said "she didn't say she is not going to help me but where does it end" I send her all the medical documents as well as all the receipts and i kept her in the loop the whole time aswell as I did some admin work for her while i was booked off as she said there is nothing wrong with my head or finger so i can still do admin work . Well when i asked her if she is still going to refund me the medical cost ,Her reply "I Paid the doctor and thats how far we will go and i did not go to her doctor when she offered (But Her doctor is very expensive and i told her i have a lift to go to a doctor in my area as it is easier for me if i need to go back and she couldn't leave the other employee alone so that means when will she be able to take me as i was in alot of Pain )
My questions;
1.Who is liable for my medical costs according to law?
2.And is it not illegal to have employee's but dont pay them UIF or don't register them?
3. I work with dogs and if i get bitten how can i claim or Get medical help if she did not register me at the fund as we get dogs that can be quite rough and nippy.?
4. What is the right proses to follow regarding this issue ?

Sorry for the long post but i wanted to tell the whole story so that you can see the whole picture.

Your help would be greatly appreciated as this is my third job in my life and i dont know my rights as an employee and iam sick & tired of being bullied .