Diploma struggles

I did a Daycare diploma almost 2 years ago with them, abd i'm still waiting for my diploma. I paid them in full but now they can't give me my diploma. I have send many emails,i phoned many times and they just put me through to somebody that doesn't even have a clue what i'm talking about. I even went to their branch in PE many a times but they also can't help me. If this is the case i would have to involve the law,or they can just give my money back ASAP.