You may be on the o2 8Meg capped service, but your modem is already running in ADSL2+ mode
DSL Type: G.992.5 annex A is what tells us that. G.992.5 means ADSL2+
You are currently connected at just 2288Kbps which is awfully low for your line attenuation (line length) of 33.5dB.
You should really be connecting at the full 8Meg now, based on the data. So suggests there may be a wiring issue in the property.
Can you connect the ADSL modem to the test socket which is underneath the removeable faceplate on the master socket (phone book has more details on this) and post the figures from the modem again.