Done the same , cacelled my DD - they have communicated they will send a final bill due 1st Nov - in all correspondence i have included the email they sent stating i could cancel ( i had other comms that said i could not ).

i have also spoke with them as they sent me a PAC Code again 4 days after i transferred to giffgaff... i get the impresssion that ALL csr staff have not been given clear guidance on this.

will update with my final bill....