Dropping a Btech stubject after the first year?

My sixth form didn't really tell me much about the course i was going to take (Forensic Science), so i assumed it would be entirely crime scene based, thinking it would be fun and interesting. Also this year i'm doing Physics, maths and chemistry A levels, and so i wanted to have an easy subject to do on the side. After while I found the subject to be a drag, waiting for it to get better, it had to. During one parents evening I was told what the actual name of the course was (Applied science) and that my teacher was surprised that i was taking the subject because of my other studies being full A levels. I've sort of always believed that i could drop any subject after the first year, after being told numerous times, and so i kept on with it doing the tasks. After a while doing this became an unnecessary hurdle for me doing my other subjects and so i want to drop the subject, but after speaking to a few heads at my sixth form i'm now confused of my options, as some have said you don't get any grade/qualification if you drop the 2 year Btech, whereas some said that something would be "sorted out" not alluding to what would happen. Currently i would rather study for my other subjects than take up more of my time on the tasks set, and if dropping the subject after this year would give me nothing, than theres really no point in carrying on. But if there really was something i would get out of it then i think i can make time. Can someone please clarify?