Tier 4 - change sponcer while visa extention is in process??

[jrmerchant]

hi,
a new member so please excuse me in case i tread a few toes.
i need guidance in this mess there is with my education & the ukba with regard to my being able to complete my degree.

i have applied for extension of stay with regard to T4 student visa.
the scenario is such that i had some issues with a london university(highly trusted) and had to leave my course half way through. and while my leave to remain was getting over and my education has not completed, i enrolled in a college (b rated) for Post grad diploma with the fee amount of £4500. as, at the time i had seen no hope from the university's side. with the hope of salvaging whatever is left of my education qualifications, i submitted my application to the ukba for review of extension of stay.
however now the university has replied. and is asking for £2000 for continuing the course that i was enrolled on (MBA)
if i wanted to stop the ukba from processing my application on the cas letter of college, get a refund from them and pay the london university the sum of £2000 and reapply for a T4 visa, would that be possible??

to obtain a cas letter from the london university i would need my passport (which is with the ukba) in this scenario i would have to withdraw the application and reapply. however my leave to remain has expired on 16th December 2010. would this classify me as an over stayer, if i were to recall my application to make amends and reapply? or is there any other way around this mess.

reason being the PGD will take one year and then a top up mba will take another 6 months.
however the continuation of the course with London university will result in my MBA completing in MAY 2011.

and i can finally go home with an MBA degree.

please advise.
thank you
J