Worried about UK born child application

[hsyasin]

Hi all,
I' a bit worried about my son's naturalization application which i sent on 16th March using old fees, which were deducted. But then got a biometric registration letter also saying that I've underpaid fees by £187.
So, this is more than a week ago, that I sent a cheque of the remainder payment with the payment page (mentioning the applicant details) via registered post and I can see that it was received on Tuesday morning last week. But the worrying thing is, the payment hasn't been taken from my account.
I posted it to same address mentioned on the letter:
UK visas and immigration,
The Capital Building,
Liverpool,
L3 9PP

[ohara]

On which date did HO receive the application? If they got it on the 18th, then you were liable to pay the new fees.

[hsyasin]

On which date did HO receive the application? If they got it on the 18th, then you were liable to pay the new fees.

Well, that's not what I'm worried about, I know I can't challenge that as they received that application on 18th. Hence I sent a cheque of additional £187.
My worry is, they give you 15days to send the correct payment and more than a week has past. So, wanted to know if anyone else was in this situation.
Coz I'm worried what if the cheque for some reason hasn't gone through (I've got the amount in the account but u know funny things happen sometimes), or whether I've made a mistake in writing the cheque or the cheque hasn't reached the correct department/person (there wasn't any mention about where to send the remaining payment, just say cheque should be to 'Accounts Officer, Home Office' and that's what I wrote)