Bad product leads to burns in mouth

I purchased an asthma inhaler from Dischem yesterday. Upon using it i immediately knew something was wrong... it tasted weird and my mouth started to burn. I have in my mouth what looks like burn wounds, on my tongue, inside my lip and the back of my throat. I went to the pharmacist for help today as my mouth is very painful. At no stage did i ask for a replacement inhaler or my money back i just wanted something for my sore mouth. They handled me like i was some sort of ***********, 4 of them discussing me in between the pill shelves. And then told me i must wait for the manager to exchange the inhaler.... when i said i am not interested in another inhaler they just showed me to the mouthwash section. I have burn wounds in my mouth due to a dud product from your store and you want me to use a mouthwash??!! As for the inhaler..... i hope that none of you ever experience this due to bad batches of products!!!!