To speak about product problems , you need the appropriate vocabulary.
Refund - an amount of money that is given back to you, especially because you are not happy with something you have bought;
Replacement - the thing or person that replaces something or someone;
To be satisfied - pleased because you have got what you wanted, or because something has happened in the way that you wanted;
Receipt - a piece of paper that proves that you have received goods or money;
Warranty - a written promise made by a company to change or repair one of its products if it has a fault;
Return - to give, send, or put something back where it came from;
Make and model number - a group of numbers that represents the product.
Examples:
If you want to return a product, you must have a receipt.
Our company offers a refund or replacement.