OK so I finally managed to get my number ported. Went like this:
Objective = Cancel current rolling monthly out of contract pay monthly NUMBER1 and just use my new simplicity through quidco porting my old number (NUMBER1) accross.
Step 1: Ring O2 and get them to turn your current monthly rolling deal to PAYG. You will get sent a PAYG sim after a day or two. Tell them you want to maintain the NUMBER1 on the new PAYG.
Step 2: Transfer any contacts from your old sim onto new and phone and backup etc. Then whack the new PAYG sim (when you get ir after a day or two) into a phone and activate it. Top up the minimum £10 (you will get this bacK).
Step 3: Wait for the day O2 stated would be your number porting day. Wait till your phone with the monthly NUMBER1 number shows as sim inactive, or you get no O2 network thing up on the screen. Turn the phone off. Discard sim. Now your new PAYG sim will soon start working with the new number. Try turning it off for an hour, then on for an hour and keep going through the day until it picks up the new number. Won't take that long though.
Step 4: Once the new PAYG sim has your old NUMBER1 number on it and works, fill out the form on O2 website under "keep my number". Fill out the form that says you want to port from PAYG to a monthly contract. You can do this on the SAME DAY as when the above stuff sstarted working. I did mine straight away whilst still recieiving texts that my PAYG was just getting up and running. Do not worry if these texts overlaps, it still works. You will need the numbers on the back of your new simplicity sim (and new phone number you got provided with that you want to get rid of) and vice versa for your PAYG sim and NUMBER1.
Step 5: Wait 1 - 4 hours. You should notice that your PAYG sim becomes inactive or cannot sync with O2 network. Turn it off. Turn your new simplicity one off. Keep turning your new simplicity one on every half hour or so and leave it for a few minutes until that one states it is inactive or cannot sync with O2. When it does this, turn it off and then turn it back on every half hour or so until it states it can find O2 network. When it does this you should get a text welcoming you and providing settings for it.
This whole thing although it looks crazy, was fairly painless. It just involves waiting about a week from the initial phone call to the O2 porting day you get assigned. Otherwise easy. The guy on the phone that advised me there was no way of doing it and was really rude, well up yours mate. You also get refunded the £!0 credit you put on the PAYG although it may only show up as a credit on your next bill.
Done. Number ported.
As for quidco cashback, mine never tracked both times I tried. Gonna put in a payment request in a week or two when it lets me.