Innerview shift cover

Hey guys :) i had an issue with my shift for this monday, i grabbed a 4am - 8am to work monday and today someone dropped a 8 am - 12 pm and i also grabbed that, now i thought that if i grabbed the 8am first and then drop the 4 am one i could still find cover for the 4 am, now its like a whole 8hr shift and wont let me drop unless its the whole thing and i just wanted to move my shift 😩 (srry if my english isn’t as good)

please any advice on what can i do, i thought about calling and calling out for the first shift but i dont know if that will work 😭