Malabar Gold & Diamonds — Difference of old gold melting

Address: D/NO : 10-1-28, Near sampanth vinyaka temple , Asilmetta Jn., waltair main road , Visakhapatnam , Andhra Pradesh, 530003

Website: Malabar gold & diamonds

I purchased worth of 4.7 lakh's on 5/6/2021 at Visakhapatnam MALABAR GOLD & DIAMONDS. Before that I got, old gold ornaments
1. 1 GOLD CHAIN
2. 1 SLIM GOLD CHAIN
3. 1 FINGER RING
4. 2 BANGLES
TOTAL WEIGHT OF ORNAMENTS IS 89GMS ..
After melting the old gold they said 76gms at the time they made rushed to me to clear the shop premises so that time i could not able to argue with the shop peoples ...
Please kindly solve my issue i'm loosing my 13gms gold {all gold are cadium and hallmark and purchased well reputed showroom's in Visakhapatnam }