My cousin lost her phone and her contract is up next month.

She's buying a new phone and wants to change network and cancel her contract. Obviously can't ring from the phone as it's been lost.

And due to the pandemic, there's no call centres available for my Aunty to call up and cancel herself (its in her name)

Are there any agents on here with a UK contact number she can use, my Aunty can provide any necessary information, just need to go through the cancellation process. As the contract is up next month, and the phones lost.