Cxd contract

We cancelled data contract (10 gig) in December and started new contract (50 gig). Debit order still being deducted for 10 gig (and 50 gig). Have many reference numbers but STILL deducting 10 gig contract. Now 4 months and still continues. Want refund for 4 months. No manager calling back to sort out - going on for months.