I am very sorry to hear that.
Did you bend the handles when storing the bag?
If not, then this bag that you had purchased is definitely defective and you should insist for a replacement. Please highlight to them that you only purchased it less than 4 months ago!
I know this sounds ridiculous considering the price that we paid but St Louis tote to me is really vulnerable to such wear and tear at handles and corners of bag.
I had this conversation at 233 Paris with store manager regarding design of St. Louis. I must very sure they are tired of hearing all these complaints from customers about the design of St. Louis. Instead of reediting the designs, they offer replacement of handles and stitching of leather corners with ADDITIONAL fees! To them, St Louis is their 'basic' entry level....
Anyway, Goyard do offer other more expensive totes which do not have problem like St Louis but in terms of price and weight and convenience of carrying around, none of them beats St Louis.