When purchasing a freezer from another city, the seller informed me by e-mail that the freezer works perfectly 100%.

Answer

If the freezer was truly not functioning or freezing as it is supposed to do, then regardless of what the seller and you had agreed, it is necessary for him to take back his product and give a refund. If a person sells an item which is rotten or does not function, then it is haraam to sell such a product, and regardless of any agreement or assurance, he must cancel the sale and make a refund. The seller did give the assurance that the product was working 100%. Not guaranteeing - is superfluous. It does not entitle one to sell carrion and a dud. He sold it with the claim of it being in perfect working order. On taking possession, if the customer finds that the product does not perform the function for which it was sold and acquired, then it is just like selling rotten meat, e.g. Sanha's or MJC's carrion meat and chicken. A new freezer which does not freeze water is like rotten meat - like Sanha's and MJC's carrion which is not 'maal' (saleable commodity) in the Shariah.