If you can't use the phone but have a support worker, you still need to give consent over the phone when your support worker calls them. Then there is no record of the call or what happened.

The only alternative is post, which is slow and prone to lost paperwork, requires a trip to the post office to pay for signed-for delivery for even minor communication.

Setting up a textphone system is complicated and sometimes expensive. Not everyone is able, especially if they don't have benefits yet.