Follow up Xiaomi S10+ Robot

FNB came back to me Yesterday regarding Xiaomi Robot S10+ the Consultant said that the Product will be Replace under Warranty. The Consultant asked if i want New one or Credit. I asked her to explain on how Credit will work because this 2nd time that i have send in the product and was replaced. The Consultant could not tell me and gave me Number of another Department which i spoke to for 30 minutes without able to assist me on my Question. I have Lost Faith in Product and all i need to know is how will Credit Process work as i do not want to Lose Money because of Productt which Continue to give problems. I have mailed FNB 3 Times since and they are just Ignoring my Mails. Nobody is following up or trying to Assist me. I have never in my Life Expierence Such Bad Service from a Company