I'm afraid your CAB adviser & the leaflet Chris linked to are out of date. The Court case which altered the position is a very recent one. It is:
Raithatha (Trustee in Bankruptcy) v Williamson ([2012] EWHC 909 Ch
If you Google that, I'm sure you can find more details, but Yes it does mean that if you are entitled to draw your pension you can be made to do so while you are still bankrupt (hence - possibly - their attempt to get your discharge delayed). That does not necessarily mean you would be made to take the £18600 lump sum. If you do take it you will have to pay it over to the OR, but my understanding of the case is that you have a choice between doing that & taking the larger pension and no lump sum. You would need to confirm that with the OR but don't automatically assume what he/she tells you is correct - query it if you are not happy with their answer.
You obviously don't have an IPA at the moment, or you would know what it is! However, if you are made to take your pension your income will increase (unless your other sources of income reduce at the same time or earlier by a similar amount). Your income & expenditure will then be re-assessed by the OR & if they deem you to have a surplus of £20 per month or more (i.e. your income is at least £20 per month more than their assessment of your expenditure for the reasonable domestic needs of yourself & anyone dependent on you) then they will propose you enter into an IPA to pay over to them all the assessed surplus each month for 3 years. If you don't agree to this they can go to Court to get an order (called an IPO) to have the same effect. Again, don't just accept their assessment if you think it is wrong - query it & if necessary take it to a higher level in the OR's office.
In your situation, your pension income will be £1150 pa higher if you do not take the lump sum, so if you are made to draw your pension while bankrupt it is clearly better for you not to take the lump sum as - once the 3 year IPA ends - you will be left with a higher pension for the rest of your life.