Account Renewed - Bill Problem Already

[#1]

OK so I renewed my contract on the 15th - £24.49 - however, apparently the old contract ending and new one starting coincided with the same date (although I think contract was to end on the 13th April) - so I have been charged £51.54 which is my out of contract price - with payment to be taken around the 23rd March.  Plusnet are not able to change the bill.

I have enquired about this and the £27.05 difference will effectively be applied as credit over the next billing cycles - £0 bill in April and £2.56 off the bill after that so should be 21.93 in May.

My question is - is it not possible to simply refund the £27.05 to my bank account after payment of 51.54 is taken around the 23rd March?

[#2]

It is properly easier to put the credit onto your account. Refunds also take time, someone has to request it, someone has to approve it/pass it to the financedepartment, someone has to then action it.
Might not be right, but next bill will probably be due before getting the money back.
Just my thoughts on it.