You uploaded an APK that is not signed with the upload certificate. You must use the same certificate. The upload certificate has fingerprint:

[Hashim pakara]

hi friends, i am facing this problem.

You uploaded an APK that is not signed with the upload certificate. You must use the same certificate. The upload certificate has fingerprint:

 

[danielyepezgarces]

The same thing happened to me and I can help you first you need to request the change of keystore, you send the .pem file when they tell you that it was changed use your new keystore and with apk-signer in the play store you can sign your apk with your keystore with format .p12

P.D: You need Keystore Explorer program to convert or create new keystore