Sonar sample rate problems in pro tools

I’m trying to complete a project i started a few years back in a friends home studio. cake walk was the program. the band broke up. the files were converted to wav and sent to me marked 48 khz 24 bit. I went to a pro tools studio to get started again and the tracks are sped up. The house engineer said there was nothing he could do on his end and that the problem occurred when the file was burned to disk. he suggested going back to the source and fire wire to a hard drive. Is this correct or is there a sample rate conversion that can be done. If i don’t have access to the original . am i done?
I know nothing can anyone help.
JGD