you may have sorted it by now.
if its the foam bolster thats gone, take one off a golf passenger seat down the scrap yards, chances are there will be a golf driver, gti or a scirroco that will have the bolster, if the material is not damaged you can easily lift the cover off and insert the new bolster either that or pack the hole in the bolster with foam, and tap this with a fabric tape, although this wont be a lasting fix. scarpyards charge peanuts for bolsters. ?2 i was charged.