REPLACING STRETCHED TYRES :@

Hi,

I have got some ATS Cups and need two stretched tyres replacing.  I have not yet replaced the tyres and cannot find anywhere which replaces them.  I have tried taking them back where I bought them from (rimstyle.com) but they do not replace tyres but simply fir new ones.  If anybody knows anywhere within an hour of Bromley, Kent area (Post Code = BR5) it would be great!

Many Thanks
Jack