Challenging a device swap valuation from Sky

[HelenGWB]

I recently swapped my device. an Apple iPhone 13 Pro 256GB Sierra Blue. When I started the swap they valued my phone at £240. They have now sent me an email, having received my old phone and have said the value has been reduced by 50% 'due to damage'. My phone was in good condition and certainly did not show the signs stated in their valuation guide which states

Damage reductions

If your device has some damage, the following damage reduction percentages will apply.

Missing or broken buttons, casing cracks, customised covers or buttons, water damaged (but fully functional)

Why isn't there an option to challenge this valuation?

[caesarome]

@HelenGWB 

If you didn't take any photos prior to sending it off all you can do is to call Sky and challenge this new valuation, if you don't come to an agreement you can cancel the swap by requesting they return the phone to you.

[HelenGWB]

Thanks, I am on the phone to Sky now. I didn't think to take photos of my phone because I foolishly trusted Sky having been a customer for 20 years!