After leaving my part month line rental not refunded in full?

[#1]

I left PN on Aug 8th and my contract didn't officially end until the 24th Aug so I was charged an early exit fee which is fair enough but although my part broadband charge was refunded in full the line rental portion from 8th - 25th which was £11.22 was only refunded £1.18?

[#2]

You relied to me by email as I made a social media post so I assume it's this one?

Dear Mr smith, Thank you for reaching me via social media, #391721122 Ref I've taken a look into the bill for you and the correct amount has been issued back to you. There is a credit of �11.22 for line rental which does show on the bill. You can view a further breakdown of the bill under the 'charges broken down' section of your bill. Please do not hesitate to get back in touch online at http://contactus.plus.net or by phone on 0800 432 0200 if we can be of further assistance. Kind regards, Samantha Lindley-Birkin

Show me where?

[#3]

I’m not in the office but from what I can see looking at your screenshot, the £11.22 is a negative amount which means that you haven’t been charged this.