I am a foreigner who has been living in Finland for about 7 years and graduated from a Finnish university. Recently, I got a training place-työkokeilu in a small cafeteria in order to improve my finnish skills. The owners are finns and they treated me quite well. I would really like to work for them as long as I can and they have given good feedback about my work. My contract continues until the end of April. While working, I always keep in mind disciplines, self-respect, faithfulness, punctuality, etc.
The problem here is the safety shoes that they demanded me to buy (since I work mostly in the kitchen, dealing with knives, hot soup or water, etc.). Before starting the training, they wanted me to buy the shoes but I refused due to my difficult financial situation. Then they gave me a pair of used safety shoes. Now after over a month, those shoes are in such a bad condition that it's impossible to use them anymore. The shoes were so broken that they no longer provided the necessary protection. And they really pushed me to buy the new pair of safety shoes by myself by letting me use the shoes without half of the shoes' bottom for a day (I need to move a lot at work). After consulting with the local TE-office (unemployment office), I quit the training since I couldn't work in the next day without the safety shoes and the owners absolutely would not purchase them for me. Then they got upset and started to talk bad things about me at least in their Facebook and I'm sure that's not all.
I would like to ask if anyone has knowledge about the issue that who was wrong in this case. Did they violate the Finnish employment law according to Työsuojelulaki/Henkilönsuojainten, apuvälineiden ja muiden laitteiden varaaminen käyttöön (http://www.finlex.fi/fi/laki/ajantasa/2 ... 0738#L2P15)? Did they do that because I am a foreigner who is so in need for a job? Or am I supposed to own a pair of safety shoes myself?
At the moment, I feel depressed and disappointed. Everywhere Finns are said to be kind, honest and so on, but why did this happen to me? I worked for them free of charge and still they appreciate 70-100€ for a pair of shoes more than my work there.

Thanks in advance.