The retailer which I purchased this faulty product says I must contact the manufacturer.

If any Retailer or Internet Seller says that you must contact the Manufacturer over any faulty product, then you should advise them of your rights.

Under the Consumer Rights Act 2015, the Retailer or Internet Seller is responsible for any faulty goods and must repair or replace the product.
If they do not, then you have the right to take it further with Trading Standards.

The manufacturer has no responsibility for faulty goods sold to the public.