How long does Apple take to respond to a case

It could take weeks.

if you purchased your phone new from apple or an Apple authorized reseller, return the device.

if you purchased the device second hand, you’re out of luck without the original owner unlocking the device.

If you are talking about "activation lock" (an anti-theft measure), AND if you cannot remember the old Apple ID & Password (even using these instructions:--> If you forgot your Apple ID email address or phone number - Apple Support or these:--> If you forgot your Apple ID password - Apple Support ) neither we, just users like you, nor Apple can help you, sorry, unless you are the original owner and you still have the proof of purchase (receipt/invoice reporting your device’s IMEI or Serial Number). Should be this case, start your request using this link: https://al-support.apple.com/#/additional-support

Shouldn’t be this case, activation lock can be removed only by the previous owner, with the credentials that were used to activate that iPhone/iPad. Without those credentials, that device is useless to you.

You can also take a look at this support article:--> How to removeActivation Lock- Apple Support

Regards

Giulio