The page you have linked to is the eBay product library entry (hence the /p/ instead of /item/in the URL), which isn't a listing as such. If there were multiple sellers offering the same product they'd all appear on this page. As yours is the only current listing (well, the only one matched to this library entry) it looks like a listing. If a buyer clicks "See all details" they go to your listing (https://www.ebay.co.uk/itm/277759471882) with the correct title. 

Unfortunately if someone clicks "Buy It Now" from the product library page they go straight to checkout, where there's only a (slim) chance they will notice that the title has changed from "5 Rolls X..." to "1 Roll of...". 

Years ago when the product library (catalogue) was introduced there was a way of reporting incorrect entries, but I don't know how this is handled now (if at all). I searched for "product library" in eBay help and got this: 

"I'm having trouble understanding that. Please rephrase or add a few details about what you're trying to do."

Good luck!