Damage shoes

I bought winter shoes in June but i dont remember the exact date i wore them 3 x then i notice that they are tearing apart in a way that they cant be fixed. I took them to Rage on 7 of July they told me that head office is not answering their call, i left the shoes there and came back the folowing day they said there is no answer at head office i left and told them i will came back monday meaning today the 13th of July. Today they told me that i cannot be assisted because i do not have the slip. I phone their headoffice they answered and told me that i was suppose to read at the back of the slip cause its return no exchange without slip. So im stuck with damage shoes that cannot be replaced. Are ask them how can one keep the slip of clothing that fits?