Contract Dispute with Supplier Over Defective Goods Delivery

We ordered manufacturing components from a supplier in July. The goods arrived with significant defects that weren't caught until we'd integrated them into our own products. We've asked for a refund or replacement, but they're refusing to engage meaningfully. We need legal advice on our contractual rights, whether we have grounds for a claim, and the best way forward without escalating costs unnecessarily. The contract is fairly standard but I want to understand our position properly before we decide on next steps.