Harassing a disabled customer about returning equipment

Since cancelling our contract my disabled wife has been hassled repeatedly for the return of equipment. The emails ask for a changing selection of kit. We have sent everything back and have the Yodel receipts to prove it. Today she received the fourth email demanding the return of the VOIP Battery emergency backup phone that we had because of her health issues, should the broadband phone have failed. This time it's an offer to come to collect it. We have complained twice to Sunderland by post. I'm reporting Virgin to Trading Standards Scotland but is there anything else I can do to stop them? I do not want to phone customer services, because the abysmal quality of their service is the reason we cancelled our contract.