It might help to say that you’re aware that “traders have a responsibility of care under the Consumer Rights Act 2015”.
If they have to pay the cost of replacing the item, the maximum they’re obliged to offer you is the value of the belongings when they were left, not what they would cost to replace as new.
You’ll probably be asked to provide evidence of how much it originally cost - for example, a receipt. The dry cleaner can then offer you a reduced amount depending on the condition of the item - you’ll have to negotiate the cost with them.
or else give a legal notice to the dry cleaner and file a petition in the consumer forums.