Unsatisfied customer

I've been to Supa Quick in Devland to try to exchange a defective battery as it was bought at their store. I couldn't find the invoice for the battery due to relocation. Because the battery has a special number engraved on it which identifies that the battery was bought there but because of not having the receipt they did not want to exchange the battery for me. The battery is still not changed and I am unable to use my car due to this matter. What does a person have to do in order to get assistance from supa quick. Is this how you treat your customers after they have paid for your services, I am so angry and I feel like my rights were violated. Where does Supa Quick expect me to run to in order to get assistance.