PIP Hearing aid(s)

So,heres an update;I had a call from the hospital offering me a hearing test the next day as there had been a cancellation.Basically The test showed I needed aids in both ears which would be fitted in 6 weeks time.I sent this information to the pip DM but have been refused 2 points for 7b, Is this because I havent used them for 3 months before my claim ? and if so in 3 months time do I send a change of circumstances letter to them or will I have to go through a whole new assessment? many thanks.