iTunes is splitting up an album

i have a Russian album that has over 150 songs with various artist. when adding to iTunes they get split up into single albums and i went through the process of getting info and making it the same compilation but after doing that once all the single album's become greyed out when clicking get info and i cant do anything. so what do i do? I recently had the same problem with a TOP 100 singles album but didn't run into the greyed out issue.