We have a problem which I cant solve. Where a wholesalers product reference includes an alpha as well as numerals Viart shop happily accepts the first upload, but if you update absolutely identical file rather that ignoring(or if there are changes updating) it always adds new record. Tried for hours trying to solve this - Any ideas please

Does your update include the product id of the item?
 
If your talking about a new item upload, then uploading again with update, the update file needs the product id with it that was automatically generated after you first uploaded it.
 
One way to get a product id, and also have a csv ready for update, is to export the product with the product id field and the field(s) you want to update.