Poor shoes quality and un-understaning staff

One star is lucky for them as their staff is clearly confused and now i need to deal with working with faulty workwear. About 4 months ago i purchased safety boots and i was told the shoes have a month guarentee. After a month i threw away the invoice as the guarantee have passed, ive started noticing the shoes are starting to tear and break down. I then went back to the Jonsson depo in Kimberley to show then the shoes and wanted an explaination as i only buy Jonsson shoes and its the first time they break down like this, since i usually walk them inside out, thats how tough they are! I was then contacted by a representative asking me for an invoice, i told them i threw it away after the 1 month as the lady said she knows when it was bought but one month guarenee have passed. Now they resist doing anything about the matter instead they tell me sorry hq say no slip no credit or replace!!! Its the first time i see a Jonsson boot do this and its unacceptable that they dont want to help me with this!!!! This makes me question should i go for another brand that will back me and thatvwould last or buy boots every 2 months!!!