Spencers — Part order delivered but charged for undelivered items and spoiled items

I had placed an order on 26-5-20 which was partly delivered on 27-5-20 and whatever was showing in invoice was also not delivered in full.Most of the perishables were spoilt and even after complaining no action was taken.
I had even complained through Facebook messenger and through e mails but nobody is bothered.They should have picked up the inferior quality items I reported and refunded for them but they didn’t.2 of the items showing in invoice as delivered were still missing -one was confirmed by Deliveryman and the ridge guard was delivered only 1/2 kg instead of 1kg and that too was mostly spoilt.
Kindly help me to get the refund processed