Ring Certificate

I bought my Rings on Laybye in 2021 August. On collection of the Rings the sales lady adviced i will get my certificate emailed in a week or two. I kept on calling the store on follow-up of the certificate but i was told i cant be assisted because i misplaced my receipt. I misplaced my receipt but I bought my Rings on Laybye. I thought the store would have a record of my purchase and i know financial records are kept for 5 years. 2 weeks later after I collected the Rings I went back to resize my Ring but I was told I can't be assisted because I have lost my receipt. I'm so puzzled that That I can not be assisted yet Thuli from American Swiss says that she can see my Laybye but records are kept for 6months from purchase but the industry says financial records I kept for 5years. How will I get assistance as I have an over-sized ring No certificate for the Rings. I am truly disappointed in the service recieved from American Swiss Mall@carnival.