DLA Change of Circumstances done over the phone

Hello
I wondered if anyone else has had this happen. We needed to report a change in circumstances for one of my children's DLA. 

We called today and spoke to someone who then said they would put us through to discuss it with a decision maker. The lady we were transferred to talked to explained she was a decision maker and that they were trialing doing CoC over the phone to see if they could make a decision and only send out forms if they'd need more information.
She spoke to us for about 20 minutes, asking lots of questions about the change we were wanting to report and at the end of the call explained that she won't be sending out a form as she felt she had enough information to make a decision and was increasing my child's award from MRC to HRC for 2 years and that we'd receive a letter in the post in the next 7 days. 

Has anyone else experienced this?