my only other advice is to take the cushion off,i hope its a cushion and not anywhere else and that its not a fixed cushion and take it to your local re upholster and see if he can replace it,that is if its bad.some how i get the idea that you bought the suite from can i say it, dfs.go back to them and demand that they do something,i know its like getting blood from a stone,but its still garanteed,as the leather is not really as hard wearing as it should,and the shop will know of the quality,they will do there best to refuse.
this is something to think about,i used to make leather suites,they used to leave the factory at a price of around £600,the shops they went to charged 3k,
but before this i worked for a small mail order upholstery factory in wales,the company i worked for had customers as far a field as spain,the customer got what they wanted ??(brand marks ,stitches etc)in the places they wanted,only ever used grade 1 scotish leather (smelt lovly and creamy)used solid beech frames,never had one complaint,but letters of pure satisfaction,then we merged with another company,and sold to the shops using splits,we had suites cushions armpads all come back,simply because of the quality of the leather.
i would not like to put people off on buying suites from shops,buy the waxy looking 2 tone leather suite its tougher or go to a small firm which advertises in the glossies and get what you want,may be dearer but you get what you pay for.