What are my rights I am not being paid right from work!?

Long story short I have been paid wrong from my job for the past 5 months. I work in retail part time as I am a uni student. I have been to EVERY manger in the store and the keep telling me its sorted and it will go in next payday. Its bull **** its not happened. I have rang the stores HR department and they said its down to pay role. who wont talk to me as they are under strict instructions to only speak to team managers. No staff are allowed the phone number and hr wont give it to me. I work for boots if thats help. I am at the end of the line and going crazy what are my actual legal rights!!!