Shop told me that i cannot change my iphone4s because The warranty is out from Humidity..

Here is the article about it:

iPhone and iPod: Liquid damage is not covered by warranty

Since we are all users here just like you, we can't do anything about decisions made by Apple.

You'll have to pay for a replacement:

Out-of-Warranty Service

If you own an iPhone that is ineligible for warranty service but is eligible for Out-of-Warranty (OOW) Service, Apple will service your iPhone for the Out-of-Warranty Service fee listed below.

iPhone model	Out-of-Warranty Service
iPhone 5	$229
iPhone 4S	$199
iPhone 4, iPhone 3GS, iPhone 3G, Original iPhone	$149

A $6.95 shipping fee will be added if service is arranged through Apple and requires shipping. All fees are in U.S. dollars and are subject to local tax.

When setting up out-of-warranty service, Apple will request credit card pre-authorization for the maximum service fee listed above. This amount will be deducted from your credit limit. The final service fee we charge will be determined during testing and may be less than the service fee listed above.

Certain damage is ineligible for out-of-warranty service, including catastrophic damage, such as the device separating into multiple pieces, and inoperability caused by unauthorized modifications. However, an iPhone that has failed due to contact with liquid may be eligible for out-of-warranty service.

Apple reserves the right to determine whether or not your iPhone is eligible for Out-of-Warranty service. iPhones that are repaired or replaced have a 90-day limited hardware warranty or assume the remainder of your standard warranty or AppleCare service contract coverage, whichever is longer. Please see Apple's Repair Terms And Conditions for further details.

Message was edited by: Ingo2711