Have you received any response from DCB Legal to the email you sent?
Don't worry about the mediation call. It is not part of the judicial process. However, I suggest you take the call and ask the following points:
When the mediator calls“
For the record: the claimant has already cancelled the charge. I have this in writing. Please note that on the mediation record. Now, before we proceed, confirm from the claimant’s side:1) Is the person you’re speaking to an authorised person (or exempt under supervision) with personal authority to discontinue today?
2) Will they confirm now that the claim is discontinued and state when the N279 will be filed and served?
Please relay their answers and record them.”
If authority + discontinuance confirmed“Thank you. My position is £0. Please record that discontinuance is confirmed by an authorised person, and the N279 filing/serving time given. That concludes the mediation.”
If “charge cancelled” but no authority/no discontinuance“Please record: claimant says the charge is cancelled, but no authorised person has confirmed discontinuance and no N279 details have been provided. My position is £0. Mediation cannot progress. I invite immediate discontinuance and will rely on this on costs (CPR 27.14(2)(g)).”
If mediator refuses to confirm/record“Please record that I have written proof the charge is cancelled, that I asked for authorised status and N279 details, and that this was refused. My position is £0. I will rely on this on costs.”
What to report back“
Cancellation noted Y/N; authorised status Y/N; discontinuance confirmed Y/N; N279 time given Y/N; refusal recorded Y/N.”